Re: [PATCH 0/4] ath10k: a few incorrect return handling fix-up

From: Sergei Shtylyov
Date: Tue Dec 30 2014 - 13:39:29 EST

On 12/30/2014 09:28 PM, Nicholas Mc Guire wrote:

wait_for_completion_timeout does not return negative values so the tests
for <= 0 are not needed and the case differentiation in the error handling
path unnecessary.

I decided to verify your statement and I saw that it seems wrong.
do_wait_for_common() can return -ERESTARTSYS and the return value gets
returned by its callers unchanged.

the -ERESTARTSYS only can be returned if state matches but
wait_for_completion_timemout passes TASK_UNINTERRUPTIBLE
so signal_pending_state will return 0 and never negativ

my understanding of the callchain is:
wait_for_completion_timemout with TASK_UNINTERRUPTIBLE
-> wait_for_common(...TASK_UNINTERRUPTIBLE)
-> __wait_for_common(...TASK_UNINTERRUPTIBLE)
-> do_wait_for_common(...TASK_UNINTERRUPTIBLE)
-> signal_pending_state(TASK_UNINTERRUPTIBLE...)

static inline int signal_pending_state(long state, struct task_struct *p)
return 0;

Right. I didn't look into TASK_UNINTERRUPTIBLE thing before sending my mail.

so wait_for_completion_timemout should return 0 or 1 only

0 or the remaining time, to be precise.

patch was only compile tested x86_64_defconfig + CONFIG_ATH_CARDS=m

patch is against linux-next 3.19.0-rc1 -next-20141226

Rather patches. It would have been better to send one patch instead of
4 patches with the same name.

sorry for that - I had split it into separate patches as it was
in different files - giving them the same name of course was a bit

You should have mentioned the modified files in the subject. But IMHO it would be better to have just one patch.

please do give it one more look - if the above argument is invalid
I apologize for the noise.

It's me who should apologize. :-<


WBR, Sergei

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at