Messages in this thread | | | Subject | Re: [RFC PATCH 06/17] net: ipa: Add timeout for ipa_cmd_pipeline_clear_wait | From | Alex Elder <> | Date | Wed, 13 Oct 2021 17:29:45 -0500 |
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On 9/19/21 10:08 PM, Sireesh Kodali wrote: > From: Vladimir Lypak <vladimir.lypak@gmail.com> > > 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 <vladimir.lypak@gmail.com> > Signed-off-by: Sireesh Kodali <sireeshkodali1@gmail.com>
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
> --- > 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) >
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