From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 0/4] ath10k: a few incorrect return handling fix-up Date: Tue, 30 Dec 2014 21:39:13 +0300 Message-ID: <54A2F151.6040205@cogentembedded.com> References: <1419942046-17985-1-git-send-email-der.herr@hofr.at> <54A2DE7C.1050602@cogentembedded.com> <20141230182842.GA18361@opentech.at> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: Kalle Valo , Michal Kazior , Ben Greear , Chun-Yeow Yeoh , Yanbo Li , ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Nicholas Mc Guire Return-path: In-Reply-To: <20141230182842.GA18361@opentech.at> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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) > { > if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) > 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 >>> CONFIG_ATH10K=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 > brain-dead. 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. :-< > thx! > hofrat WBR, Sergei