From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [RFC] Host1x/TegraDRM UAPI Date: Thu, 25 Jun 2020 03:59:27 +0300 Message-ID: References: <9b06b7ec-f952-2561-7afb-5653514cd5d3@kapsi.fi> 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-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mikko Perttunen , Thierry Reding , Jon Hunter , David Airlie , Daniel Vetter , sumit.semwal-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, gustavo-THi1TnShQwVAfugRpC6u6w@public.gmane.org Cc: "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , dri-devel , talho-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, bhuntsman-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org List-Id: linux-tegra@vger.kernel.org 25.06.2020 02:18, Dmitry Osipenko пишет: > 23.06.2020 15:09, Mikko Perttunen пишет: >> struct drm_tegra_channel_submit { >>         __u32 channel_id; >>         __u32 flags; >> >>         /** >>          * [in] Timeout in microseconds after which the kernel may >>          *   consider the job to have hung and may reap it and >>          *   fast-forward its syncpoint increments. >>          * >>          *   The value may be capped by the kernel. >>          */ >>         __u32 timeout; >> >>         __u32 num_syncpt_incrs; >>         __u32 num_relocations; >>         __u32 num_commands; >> >>         __u64 syncpt_incrs; >>         __u64 relocations; >>         __u64 commands; > > Do we really need to retain the multi-gather support? The code-bloat > (both userspace and kernel driver) is very significant just for > preparing and patching of the multi-buffer cmdstreams. > > If userspace runs out of a free space within the pushbuffer, then it > should simply reallocate a larger pushbuffer. > > I'm suggesting that we should have a single gather per-job, any objections? > Oh, I just recalled that the later Host1x versions do not allow to switch class from gather! Let me think a bit more about it..