From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752169AbdKQJvu (ORCPT ); Fri, 17 Nov 2017 04:51:50 -0500 Received: from foss.arm.com ([217.140.101.70]:60994 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751777AbdKQJvp (ORCPT ); Fri, 17 Nov 2017 04:51:45 -0500 Cc: Sudeep Holla , Linux Kernel Mailing List , Alexey Klimov Subject: Re: [PATCH] mailbox: txdone_method shouldn't always be reset To: Bjorn Andersson , Jassi Brar References: <20171116053126.28640-1-bjorn.andersson@linaro.org> <20171116174211.GQ28761@minitux> <20171117070400.GV28761@minitux> From: Sudeep Holla Organization: ARM Message-ID: Date: Fri, 17 Nov 2017 09:51:40 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171117070400.GV28761@minitux> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/11/17 07:04, Bjorn Andersson wrote: > On Thu 16 Nov 22:47 PST 2017, Jassi Brar wrote: >> On 16 Nov 2017 23:12, "Bjorn Andersson" wrote: >> On Thu 16 Nov 09:06 PST 2017, Jassi Brar wrote: >>> diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c >>> index 674b35f..95e480e 100644 >>> --- a/drivers/mailbox/mailbox.c >>> +++ b/drivers/mailbox/mailbox.c >>> @@ -124,7 +124,8 @@ static enum hrtimer_restart txdone_hrtimer(struct >>> hrtimer *hrtimer) >>> for (i = 0; i < mbox->num_chans; i++) { >>> struct mbox_chan *chan = &mbox->chans[i]; >>> >>> - if (chan->active_req && chan->cl) { >>> + if (chan->active_req && chan->cl && >>> + chan->txdone_method == TXDONE_BY_POLL) { >> >> The hrtimer code will crash before reaching this point if the channel >> wasn't TXDONE_BY_POLL when it was created, so this part is not needed. >> >> >> We have one timer for all channels of a controller. While this channel may >> be run by ACK, some other might need to be POLLed. And we want to avoid >> polling this channel. >> > > Oh, you're right. > > But the fact that the timer function will poll channels that are > "upgraded" to ACK is a separate issue. > Ah right, I recall now that's the reason Alexey had patch introducing timer per channel. -- Regards, Sudeep