From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [RFC PATCH v6 6/9] media: tegra: Add Tegra210 Video input driver Date: Fri, 10 Apr 2020 22:45:27 +0300 Message-ID: <34d9baa0-fa1e-0b67-fb9b-343b3cba0066@gmail.com> References: <1585963507-12610-1-git-send-email-skomatineni@nvidia.com> <97b35910-4c93-123a-43a0-eb14476ed0f3@nvidia.com> <84ad4e2d-6ac1-e1f4-1c55-5edaae850631@nvidia.com> <15a879b3-8fb9-6821-3cdc-104ba583ac12@gmail.com> <0c425505-347f-7418-af7e-d121fe0d06dc@nvidia.com> <1a31cd60-739f-0660-1c45-31487d2f2128@nvidia.com> <603084a5-249a-4fe2-3646-e9335ef9ab43@nvidia.com> <7895b9c6-f27d-8939-73d7-67d785e1a8b7@nvidia.com> <15d8b525-67b5-b437-f7fd-89f80cd0d9f6@nvidia.com> <7288cacd-badc-cb01-1f4c-286dd024ca10@gmail.com> <77c88717-618f-b366-2b6a-f8b4abaa66cc@nvidia.com> <00708f34-cf45-e248-c6b0-c3d2286671ca@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-clk-owner@vger.kernel.org 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 List-Id: linux-tegra@vger.kernel.org 10.04.2020 21:59, Sowjanya Komatineni пишет: ... >> It's still not clear to me how the "pre-queued buffers" will be limited. >> I'll take another look at the v7. > > OK, but I don't understand what you mean by limit on pre-queued buffers. > > I was saying vb2 queue has min_buffers_needed which was set to 3 where > streaming will start only after 3 buffers got queued up. > > Regarding outstanding condition check to make sure no more than 2 syncpt > trigger requests are in FIFO I added it to be safe where mostly we may > not hit and also I only see capture start thread holding for it during > initial frame capture as it issues single shot for 1st 2 buffers capture > and holds 3 buffers which is already queued till at least one of those 2 > issued capture is done to make sure of not triggering syncpt condition > when fifo already has 2 pending. > > In v7, will remove setting min_buffers_needed and also outstanding > syncpt trigger check. Okay, seems I got what you're saying. Yes, the check should be removed. It's impossible to get the frame-start event while capture of the previous buffer is in-progress.