Messages in this thread | | | Date | Mon, 29 May 2023 10:02:28 +0200 | Subject | Re: [PATCH] arm64: dts: mediatek: mt8173-elm: remove panel model number in DT | From | AngeloGioacchino Del Regno <> |
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Il 26/05/23 16:24, Doug Anderson ha scritto: > Hi, > > On Fri, May 26, 2023 at 3:09 AM Icenowy Zheng <uwu@icenowy.me> wrote: >> >> Currently a specific panel number is used in the Elm DTSI, which is >> corresponded to a 12" panel. However, according to the official Chrome >> OS devices document, Elm refers to Acer Chromebook R13, which, as the >> name specifies, uses a 13.3" panel, which comes with EDID information. >> >> As the kernel currently prioritizes the hardcoded timing parameters >> matched with the panel number compatible, a wrong timing will be applied >> to the 13.3" panel on Acer Chromebook R13, which leads to blank display. >> >> Because the Elm DTSI is shared with Hana board, and Hana corresponds to >> multiple devices from 11" to 14", a certain panel model number shouldn't >> be present, and driving the panel according to its EDID information is >> necessary. >> >> Signed-off-by: Icenowy Zheng <uwu@icenowy.me> >> --- >> arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > > We went through a bunch of back-and-forth here but in the end in the > ChromeOS tree we have "edp-panel" as the "compatible" here in the > ChromeOS 5.15 tree and this makes sense. > > Reviewed-by: Douglas Anderson <dianders@chromium.org> > > ...in theory one would wish for a "Fixes" tag, but I think in previous > discussions it was decided that it was too complicated. Hardcoding the > other compatible string has always been technically wrong, but I guess > it worked at some point in time. The more correct way (as you're doing > here) needs the DP AUX bus support and the generic eDP panels, both of > which are significantly newer than the elm dts. So I guess leaving no > "Fixes" tag is OK, or perhaps you could do the somewhat weak: > > Fixes: c2d94f72140a ("arm64: dts: mediatek: mt8173-elm: Move display > to ps8640 auxiliary bus")
I remember I didn't change the compatible to panel-edp because it didn't work at that time, but it does now... I'm not sure what actually fixed that and if the commit(s) was/were backported to that suggested point, so I would leave the Fixes tag out, as that may break older kernels.
Anyway, for this commit:
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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