From b8624cd0b35daa8e5374c52cf56058d64ad71166 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Guido=20G=C3=BCnther?= <agx@sigxcpu.org>
Date: Mon, 11 Oct 2021 15:41:27 +0200
Subject: drm: mxsfb: Set fallback bus format when the bridge doesn't provide
one
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Git-commit: 1db060509903b29d63fe2e39c14fd0f99c4a447e
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
If a bridge doesn't do any bus format handling MEDIA_BUS_FMT_FIXED is
returned. Fallback to a reasonable default (MEDIA_BUS_FMT_RGB888_1X24) in
that case.
This unbreaks e.g. using mxsfb with the nwl bridge and mipi dsi panels.
Reported-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Stefan Agner <stefan@agner.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/781f0352052cc50c823c199ef5f53c84902d0580.1633959458.git.agx@sigxcpu.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/mxsfb/mxsfb_kms.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
index d1cab1166ecf..0655582ae8ed 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
@@ -362,6 +362,12 @@ static void mxsfb_crtc_atomic_enable(struct drm_crtc *crtc,
drm_atomic_get_new_bridge_state(state,
mxsfb->bridge);
bus_format = bridge_state->input_bus_cfg.format;
+ if (bus_format == MEDIA_BUS_FMT_FIXED) {
+ dev_warn_once(drm->dev,
+ "Bridge does not provide bus format, assuming MEDIA_BUS_FMT_RGB888_1X24.\n"
+ "Please fix bridge driver by handling atomic_get_input_bus_fmts.\n");
+ bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+ }
}
/* If there is no bridge, use bus format from connector */
--
2.38.1