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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 9 Mar 2022 13:56:02 +0100
Message-ID: <CAMuHMdWuWFhs5-ezh_UriPzWsZt02A2AJOTJMiszGpu_3hoqfw@mail.gmail.com>
Subject: Re: [PATCH 1/2] drm: ssd130x: Fix COM scan direction register mask
To:     Chen-Yu Tsai <wens@kernel.org>
Cc:     Javier Martinez Canillas <javierm@redhat.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>, Chen-Yu Tsai <wens@csie.org>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Wed, Mar 9, 2022 at 2:57 AM Chen-Yu Tsai <wens@kernel.org> wrote:
> From: Chen-Yu Tsai <wens@csie.org>
>
> The SSD130x's command to toggle COM scan direction uses bit 3 and only
> bit 3 to set the direction of the scanout. The driver has an incorrect
> GENMASK(3, 2), causing the setting to be set on bit 2, rendering it
> ineffective.
>
> Fix the mask to only bit 3, so that the requested setting is applied
> correctly.
>
> Fixes: a61732e80867 ("drm: Add driver for Solomon SSD130x OLED displays")
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Thanks, this fixes the vertically-mirrored display on my Adafruit
FeatherWing 128x32 OLED.
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds