Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Javier Martinez Canillas <javierm@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     Javier Martinez Canillas <javierm@redhat.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@gmail.com>,
        dri-devel@lists.freedesktop.org
Subject: [PATCH] drm/ssd130x: Change pixel format used to compute the buffer size
Date:   Thu, 13 Jul 2023 10:58:07 +0200
Message-ID: <20230713085859.907127-1-javierm@redhat.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The commit e254b584dbc0 ("drm/ssd130x: Remove hardcoded bits-per-pixel in
ssd130x_buf_alloc()") used a pixel format info instead of a hardcoded bpp
to calculate the size of the buffer allocated to store the native pixels.

But that wrongly used the DRM_FORMAT_C1 fourcc pixel format, which is for
color-indexed frame buffer formats. While the ssd103x controllers don't
support different single-channel colors nor a Color Lookup Table (CLUT).

Both formats use eight pixels/byte, so in practice there is no functional
changes in this patch. But still the correct pixel format should be used.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

 drivers/gpu/drm/solomon/ssd130x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index b3dc1ca9dc10..afb08a8aa9fc 100644
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -153,7 +153,7 @@ static int ssd130x_buf_alloc(struct ssd130x_device *ssd130x)
 	const struct drm_format_info *fi;
 	unsigned int pitch;
 
-	fi = drm_format_info(DRM_FORMAT_C1);
+	fi = drm_format_info(DRM_FORMAT_R1);
 	if (!fi)
 		return -EINVAL;
 
-- 
2.41.0