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[91.78.208.152]) by smtp.googlemail.com with ESMTPSA id 12sm1836804ljq.0.2020.04.23.16.25.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Apr 2020 16:25:49 -0700 (PDT) Subject: Re: [RFC PATCH v9 6/9] media: tegra: Add Tegra210 Video input driver To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, frankc@nvidia.com, hverkuil@xs4all.nl, sakari.ailus@iki.fi, helen.koike@collabora.com Cc: sboyd@kernel.org, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org References: <1587536339-4030-1-git-send-email-skomatineni@nvidia.com> <1587536339-4030-7-git-send-email-skomatineni@nvidia.com> <7e473fa9-0409-d868-e818-2e7928a8acca@gmail.com> <3691c4b5-1ecc-2ad3-23ed-72ef6b8d25fa@nvidia.com> From: Dmitry Osipenko Message-ID: Date: Fri, 24 Apr 2020 02:25:48 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <3691c4b5-1ecc-2ad3-23ed-72ef6b8d25fa@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 24.04.2020 02:20, Sowjanya Komatineni пишет: > > On 4/23/20 4:19 PM, Sowjanya Komatineni wrote: >> >> On 4/23/20 4:16 PM, Dmitry Osipenko wrote: >>> External email: Use caution opening links or attachments >>> >>> >>> 22.04.2020 09:18, Sowjanya Komatineni пишет: >>>> +static int chan_capture_kthread_start(void *data) >>>> +{ >>>> +     struct tegra_vi_channel *chan = data; >>>> +     struct tegra_channel_buffer *buf; >>>> +     int err = 0; >>>> + >>>> +     set_freezable(); >>>> + >>>> +     while (1) { >>>> +             try_to_freeze(); >>>> + >>>> +             wait_event_interruptible(chan->start_wait, >>>> + !list_empty(&chan->capture) || >>>> +                                      kthread_should_stop()); >>>> + >>>> +             if (kthread_should_stop()) >>>> +                     break; >>>> + >>>> +             /* >>>> +              * Source is not streaming if error is non-zero. >>>> +              * So, do not dequeue buffers on capture error. >>>> +              */ >>>> +             if (err) >>>> +                     continue; >>> This will result in an endless loop, I suppose it wasn't the intention. >> >> no it will not. on error we report vb2_queue_error which will do >> streaming stop request. >> >> So thread will be stopped on streaming stop request thru kthread stop >> signal > To be clear on error it reports vb2 queue error and waits for stop > streaming to happen If thread should exit on error, then it should do it on the actual error. Otherwise it looks very error-prone.