Re: [RFC PATCH 06/17] net: ipa: Add timeout for ipa_cmd_pipeline_clear_wait
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From: Alex Elder <hidden>
Date: 2021-10-13 22:29:55
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linux-arm-msm, lkml, phone-devel
On 9/19/21 10:08 PM, Sireesh Kodali wrote:
From: Vladimir Lypak <redacted> Sometimes the pipeline clear fails, and when it does, having a hang in kernel is ugly. The timeout gives us a nice error message. Note that this shouldn't actually hang, ever. It only hangs if there is a mistake in the config, and the timeout is only useful when debugging. Signed-off-by: Vladimir Lypak <redacted> Signed-off-by: Sireesh Kodali <redacted>
This is actually an item on my to-do list. All of the waits for GSI completions should have timeouts. The only reason it hasn't been implemented already is that I would like to be sure all paths that could have a timeout actually have a reasonable recovery. I'd say an error message after a timeout is better than a hung task panic, but if this does time out, I'm not sure the state of the hardware is well-defined. -Alex
quoted hunk ↗ jump to hunk
--- drivers/net/ipa/ipa_cmd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/drivers/net/ipa/ipa_cmd.c b/drivers/net/ipa/ipa_cmd.c index 3db9e94e484f..0bdbc331fa78 100644 --- a/drivers/net/ipa/ipa_cmd.c +++ b/drivers/net/ipa/ipa_cmd.c@@ -658,7 +658,10 @@ u32 ipa_cmd_pipeline_clear_count(void) void ipa_cmd_pipeline_clear_wait(struct ipa *ipa) { - wait_for_completion(&ipa->completion); + unsigned long timeout_jiffies = msecs_to_jiffies(1000); + + if (!wait_for_completion_timeout(&ipa->completion, timeout_jiffies)) + dev_err(&ipa->pdev->dev, "%s time out\n", __func__); } void ipa_cmd_pipeline_clear(struct ipa *ipa)