kernel/lis3-improve-handling-of-null-rate.patch

From 16433a227cab8cd36cc1342b51cd27162e3478d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89ric=20Piel?= <eric.piel@tremplin-utc.net>
Date: Thu, 3 Nov 2011 16:22:40 +0100
Subject: [PATCH] lis3: improve handling of null rate

When obtaining a rate of 0, we would disable the device supposely
because it seems to behave incorectly. It actually only comes from the
fact that the device is off and on lis3dc it's reflected in the rate.
So handle this nicely by just waiting a safe time, and then using the
device as normally.

Bugzilla: 785814
Upstream-status: ??

Signed-off-by: ??ric Piel <eric.piel@tremplin-utc.net>
---
 drivers/misc/lis3lv02d/lis3lv02d.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/lis3lv02d/lis3lv02d.c b/drivers/misc/lis3lv02d/lis3lv02d.c
index 3ef4627f9cb1..2b2d2e8e5eeb 100644
--- a/drivers/misc/lis3lv02d/lis3lv02d.c
+++ b/drivers/misc/lis3lv02d/lis3lv02d.c
@@ -216,7 +216,8 @@ static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
 /* conversion btw sampling rate and the register values */
 static int lis3_12_rates[4] = {40, 160, 640, 2560};
 static int lis3_8_rates[2] = {100, 400};
-static int lis3_3dc_rates[16] = {0, 1, 10, 25, 50, 100, 200, 400, 1600, 5000};
+/* LIS3DC: 0 = power off, above 9 = undefined */
+static int lis3_3dc_rates[16] = {0, 1, 10, 25, 50, 100, 200, 400, 1600, 5000, -1, -1, -1, -1, -1, -1};
 static int lis3_3dlh_rates[4] = {50, 100, 400, 1000};
 
 /* ODR is Output Data Rate */
@@ -231,12 +232,11 @@ static int lis3lv02d_get_odr(struct lis3lv02d *lis3)
 	return lis3->odrs[(ctrl >> shift)];
 }
 
-static int lis3lv02d_get_pwron_wait(struct lis3lv02d *lis3)
+static int lis3lv02d_wait_pwron(struct lis3lv02d *lis3)
 {
 	int div = lis3lv02d_get_odr(lis3);
-
-	if (WARN_ONCE(div == 0, "device returned spurious data"))
-		return -ENXIO;
+	if (div <= 0)
+		div = 1; /* maximum delay */
 
 	/* LIS3 power on delay is quite long */
 	msleep(lis3->pwron_delay / div);
@@ -303,7 +303,7 @@ static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
 
 	lis3->read(lis3, ctlreg, &reg);
 	lis3->write(lis3, ctlreg, (reg | selftest));
-	ret = lis3lv02d_get_pwron_wait(lis3);
+	ret = lis3lv02d_wait_pwron(lis3);
 	if (ret)
 		goto fail;
 
@@ -314,7 +314,7 @@ static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
 
 	/* back to normal settings */
 	lis3->write(lis3, ctlreg, reg);
-	ret = lis3lv02d_get_pwron_wait(lis3);
+	ret = lis3lv02d_wait_pwron(lis3);
 	if (ret)
 		goto fail;
 
@@ -434,7 +434,7 @@ int lis3lv02d_poweron(struct lis3lv02d *lis3)
 		}
 	}
 
-	err = lis3lv02d_get_pwron_wait(lis3);
+	err = lis3lv02d_wait_pwron(lis3);
 	if (err)
 		return err;
 
-- 
1.9.3