579 lines
20 KiB
Diff
579 lines
20 KiB
Diff
|
From 5118c9aeafecbfa5c2a49d757c882c6033828e7e Mon Sep 17 00:00:00 2001
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||
|
From: Lyude Paul <lyude@redhat.com>
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Date: Fri, 6 Mar 2020 18:46:19 -0500
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Subject: [PATCH 1/4] drm/dp_mst: Rename drm_dp_mst_is_dp_mst_end_device() to
|
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|
be less redundant
|
||
|
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|
It's already prefixed by dp_mst, so we don't really need to repeat
|
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|
ourselves here. One of the changes I should have picked up originally
|
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when reviewing MST DSC support.
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There should be no functional changes here
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Cc: Mikita Lipski <mikita.lipski@amd.com>
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Cc: Sean Paul <seanpaul@google.com>
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Cc: Hans de Goede <hdegoede@redhat.com>
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Signed-off-by: Lyude Paul <lyude@redhat.com>
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---
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drivers/gpu/drm/drm_dp_mst_topology.c | 10 +++++-----
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1 file changed, 5 insertions(+), 5 deletions(-)
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diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
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index cce0b1bba591..9188c53f5c96 100644
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--- a/drivers/gpu/drm/drm_dp_mst_topology.c
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+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
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@@ -1935,7 +1935,7 @@ static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
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return parent_lct + 1;
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}
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-static bool drm_dp_mst_is_dp_mst_end_device(u8 pdt, bool mcs)
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+static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
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{
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switch (pdt) {
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case DP_PEER_DEVICE_DP_LEGACY_CONV:
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@@ -1965,13 +1965,13 @@ drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
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/* Teardown the old pdt, if there is one */
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if (port->pdt != DP_PEER_DEVICE_NONE) {
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- if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
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+ if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
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/*
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* If the new PDT would also have an i2c bus,
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|
* don't bother with reregistering it
|
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*/
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if (new_pdt != DP_PEER_DEVICE_NONE &&
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|
- drm_dp_mst_is_dp_mst_end_device(new_pdt, new_mcs)) {
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+ drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
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|
port->pdt = new_pdt;
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|
port->mcs = new_mcs;
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|
return 0;
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|
@@ -1991,7 +1991,7 @@ drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
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|
port->mcs = new_mcs;
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|
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|
if (port->pdt != DP_PEER_DEVICE_NONE) {
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|
- if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
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+ if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
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|
/* add i2c over sideband */
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|
ret = drm_dp_mst_register_i2c_bus(&port->aux);
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} else {
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@@ -2172,7 +2172,7 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
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}
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|
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|
if (port->pdt != DP_PEER_DEVICE_NONE &&
|
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|
- drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
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+ drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
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|
port->cached_edid = drm_get_edid(port->connector,
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|
&port->aux.ddc);
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|
drm_connector_set_tile_property(port->connector);
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|
--
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|
2.25.1
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|
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From 270862e1b736dc0e7c56a48fbb61b5ec76236982 Mon Sep 17 00:00:00 2001
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|
From: Lyude Paul <lyude@redhat.com>
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|
Date: Fri, 6 Mar 2020 18:46:20 -0500
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Subject: [PATCH 2/4] drm/dp_mst: Use full_pbn instead of available_pbn for
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|
bandwidth checks
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|
|
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|
DisplayPort specifications are fun. For a while, it's been really
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|
unclear to us what available_pbn actually does. There's a somewhat vague
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explanation in the DisplayPort spec (starting from 1.2) that partially
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explains it:
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The minimum payload bandwidth number supported by the path. Each node
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updates this number with its available payload bandwidth number if its
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payload bandwidth number is less than that in the Message Transaction
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reply.
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|
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|
So, it sounds like available_pbn represents the smallest link rate in
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use between the source and the branch device. Cool, so full_pbn is just
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|
the highest possible PBN that the branch device supports right?
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|
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|
Well, we assumed that for quite a while until Sean Paul noticed that on
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some MST hubs, available_pbn will actually get set to 0 whenever there's
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|
any active payloads on the respective branch device. This caused quite a
|
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|
bit of confusion since clearing the payload ID table would end up fixing
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the available_pbn value.
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|
|
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|
So, we just went with that until commit cd82d82cbc04 ("drm/dp_mst: Add
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branch bandwidth validation to MST atomic check") started breaking
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people's setups due to us getting erroneous available_pbn values. So, we
|
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did some more digging and got confused until we finally looked at the
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definition for full_pbn:
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|
|
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The bandwidth of the link at the trained link rate and lane count
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between the DP Source device and the DP Sink device with no time slots
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allocated to VC Payloads, represented as a Payload Bandwidth Number. As
|
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with the Available_Payload_Bandwidth_Number, this number is determined
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by the link with the lowest lane count and link rate.
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That's what we get for not reading specs closely enough, hehe. So, since
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full_pbn is definitely what we want for doing bandwidth restriction
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checks - let's start using that instead and ignore available_pbn
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entirely.
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|
|
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|
Signed-off-by: Lyude Paul <lyude@redhat.com>
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Fixes: cd82d82cbc04 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
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Cc: Mikita Lipski <mikita.lipski@amd.com>
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Cc: Hans de Goede <hdegoede@redhat.com>
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Cc: Sean Paul <sean@poorly.run>
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---
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drivers/gpu/drm/drm_dp_mst_topology.c | 15 +++++++--------
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include/drm/drm_dp_mst_helper.h | 4 ++--
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2 files changed, 9 insertions(+), 10 deletions(-)
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diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
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index 9188c53f5c96..7df7676b45c4 100644
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--- a/drivers/gpu/drm/drm_dp_mst_topology.c
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+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
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@@ -2309,7 +2309,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
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port);
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}
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} else {
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- port->available_pbn = 0;
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+ port->full_pbn = 0;
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}
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}
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@@ -2404,7 +2404,7 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
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if (port->ddps) {
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|
dowork = true;
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} else {
|
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|
- port->available_pbn = 0;
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|
+ port->full_pbn = 0;
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}
|
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|
}
|
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|
|
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|
@@ -2556,7 +2556,7 @@ static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mg
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|
if (port->input || !port->ddps)
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continue;
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|
|
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- if (!port->available_pbn) {
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+ if (!port->full_pbn) {
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drm_modeset_lock(&mgr->base.lock, NULL);
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drm_dp_send_enum_path_resources(mgr, mstb, port);
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drm_modeset_unlock(&mgr->base.lock);
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@@ -3002,8 +3002,7 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
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path_res->port_number,
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path_res->full_payload_bw_number,
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path_res->avail_payload_bw_number);
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|
- port->available_pbn =
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- path_res->avail_payload_bw_number;
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+ port->full_pbn = path_res->full_payload_bw_number;
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port->fec_capable = path_res->fec_capable;
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}
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|
}
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|
@@ -3598,7 +3597,7 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
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|
|
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|
list_for_each_entry(port, &mstb->ports, next) {
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/* The PBN for each port will also need to be re-probed */
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|
- port->available_pbn = 0;
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|
+ port->full_pbn = 0;
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|
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|
if (port->mstb)
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drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
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|
@@ -4842,8 +4841,8 @@ int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
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|
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
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return -ENOSPC;
|
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|
|
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|
- if (port->available_pbn > 0)
|
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|
- pbn_limit = port->available_pbn;
|
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+ if (port->full_pbn > 0)
|
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+ pbn_limit = port->full_pbn;
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}
|
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DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch has %d PBN available\n",
|
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branch, pbn_limit);
|
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|
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
|
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|
index bcb39da9adb4..41725d88d27e 100644
|
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|
--- a/include/drm/drm_dp_mst_helper.h
|
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|
+++ b/include/drm/drm_dp_mst_helper.h
|
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|
@@ -81,7 +81,7 @@ struct drm_dp_vcpi {
|
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|
* &drm_dp_mst_topology_mgr.base.lock.
|
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|
* @num_sdp_stream_sinks: Number of stream sinks. Protected by
|
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|
* &drm_dp_mst_topology_mgr.base.lock.
|
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|
- * @available_pbn: Available bandwidth for this port. Protected by
|
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|
+ * @full_pbn: Max possible bandwidth for this port. Protected by
|
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|
* &drm_dp_mst_topology_mgr.base.lock.
|
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|
* @next: link to next port on this branch device
|
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|
* @aux: i2c aux transport to talk to device connected to this port, protected
|
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|
@@ -126,7 +126,7 @@ struct drm_dp_mst_port {
|
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|
u8 dpcd_rev;
|
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|
u8 num_sdp_streams;
|
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|
u8 num_sdp_stream_sinks;
|
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|
- uint16_t available_pbn;
|
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|
+ uint16_t full_pbn;
|
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|
struct list_head next;
|
||
|
/**
|
||
|
* @mstb: the branch device connected to this port, if there is one.
|
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|
--
|
||
|
2.25.1
|
||
|
|
||
|
From 6fceb6d9d9cdef2e26558f6b75700cc0f07a812c Mon Sep 17 00:00:00 2001
|
||
|
From: Lyude Paul <lyude@redhat.com>
|
||
|
Date: Fri, 6 Mar 2020 18:46:21 -0500
|
||
|
Subject: [PATCH 3/4] drm/dp_mst: Reprobe path resources in CSN handler
|
||
|
|
||
|
We used to punt off reprobing path resources to the link address probe
|
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|
work, but now that we handle CSNs asynchronously from the driver's HPD
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|
handling we can do whatever the heck we want from the CSN!
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|
|
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|
So, reprobe the path resources from drm_dp_mst_handle_conn_stat(). Also,
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|
get rid of the path resource reprobing code in
|
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|
drm_dp_check_and_send_link_address() since it's needlessly complicated
|
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|
when we already reprobe path resources from
|
||
|
drm_dp_handle_link_address_port(). And finally, teach
|
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|
drm_dp_send_enum_path_resources() to return 1 on PBN changes so we know
|
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|
if we need to send another hotplug or not.
|
||
|
|
||
|
This fixes issues where we've indicated to userspace that a port has
|
||
|
just been connected, before we actually probed it's available PBN -
|
||
|
something that results in unexpected atomic check failures.
|
||
|
|
||
|
Signed-off-by: Lyude Paul <lyude@redhat.com>
|
||
|
Fixes: cd82d82cbc04 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
|
||
|
Cc: Mikita Lipski <mikita.lipski@amd.com>
|
||
|
Cc: Hans de Goede <hdegoede@redhat.com>
|
||
|
Cc: Sean Paul <sean@poorly.run>
|
||
|
---
|
||
|
drivers/gpu/drm/drm_dp_mst_topology.c | 48 ++++++++++++++-------------
|
||
|
1 file changed, 25 insertions(+), 23 deletions(-)
|
||
|
|
||
|
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
|
||
|
index 7df7676b45c4..112972031a84 100644
|
||
|
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
|
||
|
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
|
||
|
@@ -2302,12 +2302,16 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
|
||
|
mutex_unlock(&mgr->lock);
|
||
|
}
|
||
|
|
||
|
- if (old_ddps != port->ddps) {
|
||
|
- if (port->ddps) {
|
||
|
- if (!port->input) {
|
||
|
- drm_dp_send_enum_path_resources(mgr, mstb,
|
||
|
- port);
|
||
|
- }
|
||
|
+ /*
|
||
|
+ * Reprobe PBN caps on both hotplug, and when re-probing the link
|
||
|
+ * for our parent mstb
|
||
|
+ */
|
||
|
+ if (old_ddps != port->ddps || !created) {
|
||
|
+ if (port->ddps && !port->input) {
|
||
|
+ ret = drm_dp_send_enum_path_resources(mgr, mstb,
|
||
|
+ port);
|
||
|
+ if (ret == 1)
|
||
|
+ changed = true;
|
||
|
} else {
|
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|
port->full_pbn = 0;
|
||
|
}
|
||
|
@@ -2401,11 +2405,10 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
|
||
|
port->ddps = conn_stat->displayport_device_plug_status;
|
||
|
|
||
|
if (old_ddps != port->ddps) {
|
||
|
- if (port->ddps) {
|
||
|
- dowork = true;
|
||
|
- } else {
|
||
|
+ if (port->ddps && !port->input)
|
||
|
+ drm_dp_send_enum_path_resources(mgr, mstb, port);
|
||
|
+ else
|
||
|
port->full_pbn = 0;
|
||
|
- }
|
||
|
}
|
||
|
|
||
|
new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
|
||
|
@@ -2556,13 +2559,6 @@ static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mg
|
||
|
if (port->input || !port->ddps)
|
||
|
continue;
|
||
|
|
||
|
- if (!port->full_pbn) {
|
||
|
- drm_modeset_lock(&mgr->base.lock, NULL);
|
||
|
- drm_dp_send_enum_path_resources(mgr, mstb, port);
|
||
|
- drm_modeset_unlock(&mgr->base.lock);
|
||
|
- changed = true;
|
||
|
- }
|
||
|
-
|
||
|
if (port->mstb)
|
||
|
mstb_child = drm_dp_mst_topology_get_mstb_validated(
|
||
|
mgr, port->mstb);
|
||
|
@@ -2990,6 +2986,7 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
|
||
|
|
||
|
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
|
||
|
if (ret > 0) {
|
||
|
+ ret = 0;
|
||
|
path_res = &txmsg->reply.u.path_resources;
|
||
|
|
||
|
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
|
||
|
@@ -3002,13 +2999,22 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
|
||
|
path_res->port_number,
|
||
|
path_res->full_payload_bw_number,
|
||
|
path_res->avail_payload_bw_number);
|
||
|
+
|
||
|
+ /*
|
||
|
+ * If something changed, make sure we send a
|
||
|
+ * hotplug
|
||
|
+ */
|
||
|
+ if (port->full_pbn != path_res->full_payload_bw_number ||
|
||
|
+ port->fec_capable != path_res->fec_capable)
|
||
|
+ ret = 1;
|
||
|
+
|
||
|
port->full_pbn = path_res->full_payload_bw_number;
|
||
|
port->fec_capable = path_res->fec_capable;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
kfree(txmsg);
|
||
|
- return 0;
|
||
|
+ return ret;
|
||
|
}
|
||
|
|
||
|
static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
|
||
|
@@ -3595,13 +3601,9 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
|
||
|
/* The link address will need to be re-sent on resume */
|
||
|
mstb->link_address_sent = false;
|
||
|
|
||
|
- list_for_each_entry(port, &mstb->ports, next) {
|
||
|
- /* The PBN for each port will also need to be re-probed */
|
||
|
- port->full_pbn = 0;
|
||
|
-
|
||
|
+ list_for_each_entry(port, &mstb->ports, next)
|
||
|
if (port->mstb)
|
||
|
drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
|
||
|
- }
|
||
|
}
|
||
|
|
||
|
/**
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--
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2.25.1
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From 20c8afc6f3f18187517411323a125dfff3c014e7 Mon Sep 17 00:00:00 2001
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From: Lyude Paul <lyude@redhat.com>
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Date: Fri, 6 Mar 2020 18:46:22 -0500
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Subject: [PATCH 4/4] drm/dp_mst: Rewrite and fix bandwidth limit checks
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Sigh, this is mostly my fault for not giving commit cd82d82cbc04
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("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
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enough scrutiny during review. The way we're checking bandwidth
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limitations here is mostly wrong:
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For starters, drm_dp_mst_atomic_check_bw_limit() determines the
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pbn_limit of a branch by simply scanning each port on the current branch
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device, then uses the last non-zero full_pbn value that it finds. It
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then counts the sum of the PBN used on each branch device for that
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level, and compares against the full_pbn value it found before.
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This is wrong because ports can and will have different PBN limitations
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on many hubs, especially since a number of DisplayPort hubs out there
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will be clever and only use the smallest link rate required for each
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downstream sink - potentially giving every port a different full_pbn
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value depending on what link rate it's trained at. This means with our
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current code, which max PBN value we end up with is not well defined.
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Additionally, we also need to remember when checking bandwidth
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limitations that the top-most device in any MST topology is a branch
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device, not a port. This means that the first level of a topology
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doesn't technically have a full_pbn value that needs to be checked.
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Instead, we should assume that so long as our VCPI allocations fit we're
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within the bandwidth limitations of the primary MSTB.
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We do however, want to check full_pbn on every port including those of
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the primary MSTB. However, it's important to keep in mind that this
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value represents the minimum link rate /between a port's sink or mstb,
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and the mstb itself/. A quick diagram to explain:
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MSTB #1
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/ \
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/ \
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Port #1 Port #2
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full_pbn for Port #1 → | | ← full_pbn for Port #2
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Sink #1 MSTB #2
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etc...
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Note that in the above diagram, the combined PBN from all VCPI
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allocations on said hub should not exceed the full_pbn value of port #2,
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and the display configuration on sink #1 should not exceed the full_pbn
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value of port #1. However, port #1 and port #2 can otherwise consume as
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much bandwidth as they want so long as their VCPI allocations still fit.
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And finally - our current bandwidth checking code also makes the mistake
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of not checking whether something is an end device or not before trying
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to traverse down it.
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So, let's fix it by rewriting our bandwidth checking helpers. We split
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the function into one part for handling branches which simply adds up
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the total PBN on each branch and returns it, and one for checking each
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port to ensure we're not going over its PBN limit. Phew.
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This should fix regressions seen, where we erroneously reject display
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configurations due to thinking they're going over our bandwidth limits
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when they're not.
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Changes since v1:
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* Took an even closer look at how PBN limitations are supposed to be
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handled, and did some experimenting with Sean Paul. Ended up rewriting
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these helpers again, but this time they should actually be correct!
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Signed-off-by: Lyude Paul <lyude@redhat.com>
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Fixes: cd82d82cbc04 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
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Cc: Mikita Lipski <mikita.lipski@amd.com>
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Cc: Sean Paul <seanpaul@google.com>
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Cc: Hans de Goede <hdegoede@redhat.com>
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---
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drivers/gpu/drm/drm_dp_mst_topology.c | 120 ++++++++++++++++++++------
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1 file changed, 94 insertions(+), 26 deletions(-)
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diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
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index 112972031a84..415bd0770eab 100644
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--- a/drivers/gpu/drm/drm_dp_mst_topology.c
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+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
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@@ -4830,41 +4830,103 @@ static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
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return false;
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}
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-static inline
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-int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
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- struct drm_dp_mst_topology_state *mst_state)
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+static int
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+drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
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+ struct drm_dp_mst_topology_state *state);
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+
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+static int
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+drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
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+ struct drm_dp_mst_topology_state *state)
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{
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- struct drm_dp_mst_port *port;
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struct drm_dp_vcpi_allocation *vcpi;
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- int pbn_limit = 0, pbn_used = 0;
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+ struct drm_dp_mst_port *port;
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+ int pbn_used = 0, ret;
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+ bool found = false;
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- list_for_each_entry(port, &branch->ports, next) {
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- if (port->mstb)
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- if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
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- return -ENOSPC;
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+ /* Check that we have at least one port in our state that's downstream
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+ * of this branch, otherwise we can skip this branch
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+ */
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+ list_for_each_entry(vcpi, &state->vcpis, next) {
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+ if (!vcpi->pbn ||
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+ !drm_dp_mst_port_downstream_of_branch(vcpi->port,
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+ mstb))
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+ continue;
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- if (port->full_pbn > 0)
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- pbn_limit = port->full_pbn;
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+ found = true;
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+ break;
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}
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- DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch has %d PBN available\n",
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- branch, pbn_limit);
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+ if (!found)
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+ return 0;
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- list_for_each_entry(vcpi, &mst_state->vcpis, next) {
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- if (!vcpi->pbn)
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- continue;
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+ if (mstb->port_parent)
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+ DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
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+ mstb->port_parent->parent, mstb->port_parent,
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+ mstb);
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+ else
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+ DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n",
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+ mstb);
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+
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+ list_for_each_entry(port, &mstb->ports, next) {
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+ ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
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+ if (ret < 0)
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+ return ret;
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- if (drm_dp_mst_port_downstream_of_branch(vcpi->port, branch))
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- pbn_used += vcpi->pbn;
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+ pbn_used += ret;
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}
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- DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch used %d PBN\n",
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- branch, pbn_used);
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- if (pbn_used > pbn_limit) {
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- DRM_DEBUG_ATOMIC("[MST BRANCH:%p] No available bandwidth\n",
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- branch);
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+ return pbn_used;
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+}
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+
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+static int
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+drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
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+ struct drm_dp_mst_topology_state *state)
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+{
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+ struct drm_dp_vcpi_allocation *vcpi;
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+ int pbn_used = 0;
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+
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+ if (port->pdt == DP_PEER_DEVICE_NONE)
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+ return 0;
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+
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+ if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
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+ bool found = false;
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+
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+ list_for_each_entry(vcpi, &state->vcpis, next) {
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+ if (vcpi->port != port)
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+ continue;
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+ if (!vcpi->pbn)
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+ return 0;
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+
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+ found = true;
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+ break;
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+ }
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+ if (!found)
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+ return 0;
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+
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+ /* This should never happen, as it means we tried to
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+ * set a mode before querying the full_pbn
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+ */
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+ if (WARN_ON(!port->full_pbn))
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+ return -EINVAL;
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+
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+ pbn_used = vcpi->pbn;
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+ } else {
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+ pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
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+ state);
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+ if (pbn_used <= 0)
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+ return 0;
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+ }
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+
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+ if (pbn_used > port->full_pbn) {
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+ DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
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+ port->parent, port, pbn_used,
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+ port->full_pbn);
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return -ENOSPC;
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}
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- return 0;
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+
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+ DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
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+ port->parent, port, pbn_used, port->full_pbn);
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+
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+ return pbn_used;
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}
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static inline int
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@@ -5062,9 +5124,15 @@ int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
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ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
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if (ret)
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break;
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- ret = drm_dp_mst_atomic_check_bw_limit(mgr->mst_primary, mst_state);
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- if (ret)
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+
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+ mutex_lock(&mgr->lock);
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+ ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
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+ mst_state);
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+ mutex_unlock(&mgr->lock);
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+ if (ret < 0)
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break;
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+ else
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+ ret = 0;
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}
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return ret;
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--
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2.25.1
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