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Fix lockdep issue in EHCI when using threaded IRQs (rhbz 1056170)

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This commit is contained in:
Josh Boyer 2014-02-24 11:09:22 -05:00
parent 8ee4982e1f
commit 4c81e23fa1
2 changed files with 66 additions and 0 deletions
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9
kernel.spec
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@ -624,6 +624,9 @@ Patch25201: cifs-sanity-check-length-of-data-to-send-before-sending.patch
#rhbz 1062833
Patch25202: dma-debug-account-for-cachelines-and-read-only-mappings.patch
#rhbz 1056170
Patch25025: usb-ehci-fix-deadlock-when-threadirqs-option-is-used.patch
# END OF PATCH DEFINITIONS
%endif
@ -1270,6 +1273,9 @@ ApplyPatch cifs-sanity-check-length-of-data-to-send-before-sending.patch
#rhbz 1062833
ApplyPatch dma-debug-account-for-cachelines-and-read-only-mappings.patch
#rhbz 1056170
ApplyPatch usb-ehci-fix-deadlock-when-threadirqs-option-is-used.patch
# END OF PATCH APPLICATIONS
%endif
@ -2049,6 +2055,9 @@ fi
# ||----w |
# || ||
%changelog
* Mon Feb 24 2014 Josh Boyer <jwboyer@fedoraproject.org>
- Fix lockdep issue in EHCI when using threaded IRQs (rhbz 1056170)
* Mon Feb 24 2014 Josh Boyer <jwboyer@fedoraproject.org> - 3.14.0-0.rc4.git0.1
- Linux v3.14-rc4
- Disable debugging options.

57
usb-ehci-fix-deadlock-when-threadirqs-option-is-used.patch Normal file
View File

@ -0,0 +1,57 @@
ehci_irq() and ehci_hrtimer_func() can deadlock on ehci->lock when
threadirqs option is used. To prevent the deadlock use
spin_lock_irqsave() in ehci_irq().
This change can be reverted when hrtimer callbacks become threaded.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
drivers/usb/host/ehci-hcd.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 4711427..0bc6410 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -685,8 +685,15 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
u32 status, masked_status, pcd_status = 0, cmd;
int bh;
+ unsigned long flags;
- spin_lock (&ehci->lock);
+ /*
+ * For threadirqs option we use spin_lock_irqsave() variant to prevent
+ * deadlock with ehci hrtimer callback, because hrtimer callbacks run
+ * in interrupt context even when threadirqs is specified. We can go
+ * back to spin_lock() variant when hrtimer callbacks become threaded.
+ */
+ spin_lock_irqsave(&ehci->lock, flags);
status = ehci_readl(ehci, &ehci->regs->status);
@@ -704,7 +711,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
/* Shared IRQ? */
if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
- spin_unlock(&ehci->lock);
+ spin_unlock_irqrestore(&ehci->lock, flags);
return IRQ_NONE;
}
@@ -815,7 +822,7 @@ dead:
if (bh)
ehci_work (ehci);
- spin_unlock (&ehci->lock);
+ spin_unlock_irqrestore(&ehci->lock, flags);
if (pcd_status)
usb_hcd_poll_rh_status(hcd);
return IRQ_HANDLED;
--
1.7.11.7
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