The patch below does not apply to the 5.8-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From bad20a2dbfdfaf01560026909506b6ed69d65ba2 Mon Sep 17 00:00:00 2001
From: Paul Cercueil paul@crapouillou.net Date: Thu, 16 Jul 2020 14:56:46 +0200 Subject: [PATCH] drm/panel-simple: Fix inverted V/H SYNC for Frida FRD350H54004 panel
The FRD350H54004 panel was marked as having active-high VSYNC and HSYNC signals, which sorts-of worked, but resulted in the picture fading out under certain circumstances.
Fix this issue by marking VSYNC and HSYNC signals active-low.
v2: Rebase on drm-misc-next
Fixes: 7b6bd8433609 ("drm/panel: simple: Add support for the Frida FRD350H54004 panel") Cc: stable@vger.kernel.org # v5.5 Signed-off-by: Paul Cercueil paul@crapouillou.net Signed-off-by: Sam Ravnborg sam@ravnborg.org Link: https://patchwork.freedesktop.org/patch/msgid/20200716125647.10964-1-paul@cr...
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index f42249b72548..8b0bab9dd075 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -1763,7 +1763,7 @@ static const struct drm_display_mode frida_frd350h54004_mode = { .vsync_start = 240 + 2, .vsync_end = 240 + 2 + 6, .vtotal = 240 + 2 + 6 + 2, - .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC, + .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, };
static const struct panel_desc frida_frd350h54004 = {