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From: dianders@chromium.org (Doug Anderson)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: rk3x: Increase wait timeout to 1 second
Date: Thu, 30 Apr 2015 14:44:07 -0700	[thread overview]
Message-ID: <1430430247-9632-1-git-send-email-dianders@chromium.org> (raw)

While it's not sensible for an i2c command to _actually_ need more
than 200ms to complete, let's increase the timeout anyway.  Why?  It
turns out that if you've got a large number of printks going out to a
serial console, interrupts on a CPU can be disabled for hundreds of
milliseconds. That's not a great situation to be in to start with
(maybe we should put a cap in vprintk_emit()) but it's pretty annoying
to start seeing unexplained i2c timeouts.

A normal system shouldn't see i2c timeouts anyway, so increasing the
timeout should help people debugging without hurting other people
excessively.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
 drivers/i2c/busses/i2c-rk3x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 019d542..72e97e30 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -72,7 +72,7 @@ enum {
 #define REG_INT_ALL       0x7f
 
 /* Constants */
-#define WAIT_TIMEOUT      200 /* ms */
+#define WAIT_TIMEOUT      1000 /* ms */
 #define DEFAULT_SCL_RATE  (100 * 1000) /* Hz */
 
 enum rk3x_i2c_state {
-- 
2.2.0.rc0.207.ga3a616c

             reply	other threads:[~2015-04-30 21:44 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-30 21:44 Doug Anderson [this message]
2015-05-01  3:40 ` [PATCH] i2c: rk3x: Increase wait timeout to 1 second Caesar Wang
2015-05-01  3:42 ` Caesar Wang
2015-05-04  8:33 ` Uwe Kleine-König
2015-05-04 15:11   ` Doug Anderson
2015-05-04 15:24     ` Uwe Kleine-König
2015-05-04 16:38       ` Doug Anderson
2015-05-05 13:10         ` Uwe Kleine-König

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