From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v2 1/2] i2c: tegra: Better handle case where CPU0 is busy for a long time Date: Mon, 27 Apr 2020 19:02:05 +0300 Message-ID: <127a2c32-e5fb-2944-3062-361b276490c0@gmail.com> References: <79f6560e-dbb5-0ae1-49f8-cf1cd95396ec@nvidia.com> <20200427074837.GC3451400@ulmo> <20200427084424.GA28817@kunai> <820200ce-17f3-18c0-6f79-3e582f45492d@gmail.com> <20200427103553.GA24446@kunai> <20200427105029.GB3464906@ulmo> <20200427153244.GF3464906@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200427153244.GF3464906@ulmo> Content-Language: en-US Sender: linux-i2c-owner@vger.kernel.org To: Thierry Reding , Wolfram Sang Cc: Jon Hunter , Laxman Dewangan , Manikanta Maddireddy , Vidya Sagar , linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 27.04.2020 18:32, Thierry Reding пишет: > On Mon, Apr 27, 2020 at 12:50:29PM +0200, Thierry Reding wrote: >> On Mon, Apr 27, 2020 at 12:35:53PM +0200, Wolfram Sang wrote: >>> On Mon, Apr 27, 2020 at 12:07:19PM +0300, Dmitry Osipenko wrote: >>>> 27.04.2020 11:44, Wolfram Sang пишет: >>>>> >>>>>> Wolfram, can you revert the following two patches for v5.7, please? >>>>>> >>>>>> 8814044fe0fa i2c: tegra: Synchronize DMA before termination >>>> >>>> This patch has nothing to do with your trouble, why do you want to >>>> revert it? >>> >>> I'll wait some more before pushing out, so you can discuss it. >> >> Okay, let me run a quick test with that second patch still applied to >> make sure it really is harmless. > > Alright, I tested v5.7-rc3 with this patch reverted: > > a900aeac2537 i2c: tegra: Better handle case where CPU0 is busy for a long time > > and the results came back positive, so I think we can leave patch: > > 8814044fe0fa i2c: tegra: Synchronize DMA before termination > > in. But then again, I see that Dmitry posted this yesterday: > > https://lkml.org/lkml/2020/4/26/481 > > which seems like it would be related to this and potentially be a > follow-up fix for some corner cases? This is a follow-up to my previous message in this thread: https://lkml.org/lkml/2020/4/23/792 > So I'm not sure how well this whole set has been tested yet. It depends on what you're meaning by the testing. We have some yet-out-of-tree real-world devices that are using APBDMA for Bluetooth, Audio, I2C (touchscreens) and etc peripherals. These devices were using the DMA patches before they were posted to the ML. > Maybe a better solution would be for the DMA synchronization patch to go > into the 5.8 queue instead to make sure we get more testing cycles. It should be fine to re-queue the patches for 5.8. I'm just a bit afraid that if patches are simply dropped now, then you won't get back to it for a year or so ;)