From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v2 0/5] 180 degrees rotation support for NVIDIA Tegra DRM Date: Tue, 16 Jun 2020 14:40:47 +0300 Message-ID: <8f789ef5-bebf-c869-784d-afda70fc1fb8@gmail.com> References: <20200614200121.14147-1-digetx@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-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Emil Velikov Cc: Thierry Reding , Thomas Zimmermann , Derek Basehore , Sam Ravnborg , Laurent Pinchart , Sean Paul , linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Linux-Kernel@Vger. Kernel. Org" , ML dri-devel List-Id: linux-tegra@vger.kernel.org 16.06.2020 01:26, Emil Velikov пишет: > Hi Dmitry, > > On Mon, 15 Jun 2020 at 08:28, Dmitry Osipenko wrote: >> >> Hello! >> >> This series adds 180° display plane rotation support to the NVIDIA Tegra >> DRM driver which is needed for devices that have display panel physically >> mounted upside-down, like Nexus 7 tablet device for example [1]. Since >> DRM panel rotation is a new thing for a userspace, currently only >> Opentegra Xorg driver handles the rotated display panel [2], but this >> is good enough for the start. >> >> Note that later on it should be possible to implement a transparent 180° >> display rotation for Tegra DRM driver which will remove the need to have >> a bleeding edge userspace that knows how to rotate display planes and I'm >> slowly working on it. For the starter we can go with the minimal rotation >> support, so it's not a blocker. >> >> This series is based on the work that was made by Derek Basehore for the >> Mediatek driver [3], his patch is included into this patchset. I added >> my tested-by tag to the Derek's patch. >> >> Please review and apply, thanks in advance! >> >> [1] https://patchwork.ozlabs.org/project/linux-tegra/patch/20200607154327.18589-3-digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org/ >> [2] https://github.com/grate-driver/xf86-video-opentegra/commit/28eb20a3959bbe5bc3a3b67e55977093fd5114ca >> [3] https://lkml.org/lkml/2020/3/5/1119 >> >> Changelog: >> >> v2: - Dropped "drm/panel: Set display info in panel attach" patch, which >> turned out to be obsolete now. >> >> - Renamed the cover-latter, hopefully this will fix the bouncing emails. >> >> Derek Basehore (1): >> drm/panel: Add helper for reading DT rotation >> >> Dmitry Osipenko (4): >> drm/panel: lvds: Set up panel orientation > > IMHO it's perfectly reasonable to report the panel orientation to > userspace, which can apply plane rotation as needed. > > Although I see that this series, alike Derek's, has a couple of issues: > - only a single panel driver is updated > - rotation is _not_ listed as supported property, in said panel > driver device-tree bindings > > My personal inclination is that we should aim for a comprehensive solution: > - wire all panel drivers, as currently documented (quick grep list below) > - document and wire-up the lvds and boe panels - as proposed by you > and Derek respectively > > HTH > Emil > > Documentation/devicetree/bindings/display/himax,hx8357d.txt:2 > Documentation/devicetree/bindings/display/ilitek,ili9225.txt:2 > Documentation/devicetree/bindings/display/ilitek,ili9341.txt:2 > Documentation/devicetree/bindings/display/ilitek,ili9486.yaml:2 > Documentation/devicetree/bindings/display/multi-inno,mi0283qt.txt:2 > Documentation/devicetree/bindings/display/panel/panel-common.yaml:2 > Documentation/devicetree/bindings/display/sitronix,st7586.txt:1 > Documentation/devicetree/bindings/display/sitronix,st7735r.yaml:2 Rotation is a common DT panel property that is described in the panel-common.yaml. This property is supported by all panel bindings because these bindings inherent the common properties from the panel-common.yaml. I don't think that it makes sense to wire up rotation property to all panel drivers at once because those drivers will be untested, at least I don't know anything about those other panels and can't test them. It will be much better to support the rotation on by as-needed basis for each panel driver individually.