The patch below does not apply to the 5.10-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 60a6b73dd821e98fe958b2a83393ccd724b306b1 Mon Sep 17 00:00:00 2001
From: Paul Cercueil paul@crapouillou.net Date: Tue, 23 Mar 2021 14:40:08 +0000 Subject: [PATCH] drm/ingenic: Fix pixclock rate for 24-bit serial panels
When using a 24-bit panel on a 8-bit serial bus, the pixel clock requested by the panel has to be multiplied by 3, since the subpixels are shifted sequentially.
The code (in ingenic_drm_encoder_atomic_check) already computed crtc_state->adjusted_mode->crtc_clock accordingly, but clk_set_rate() used crtc_state->adjusted_mode->clock instead.
Fixes: 28ab7d35b6e0 ("drm/ingenic: Properly compute timings when using a 3x8-bit panel") Cc: stable@vger.kernel.org # v5.10 Signed-off-by: Paul Cercueil paul@crapouillou.net Tested-by: H. Nikolaus Schaller hns@goldelico.com # CI20/jz4780 (HDMI) and Alpha400/jz4730 (LCD) Acked-by: Thomas Zimmermann tzimmermann@suse.de Link: https://patchwork.freedesktop.org/patch/msgid/20210323144008.166248-1-paul@c...
diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c index 09225b770bb8..389cad59e090 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -342,7 +342,7 @@ static void ingenic_drm_crtc_atomic_flush(struct drm_crtc *crtc, if (priv->update_clk_rate) { mutex_lock(&priv->clk_mutex); clk_set_rate(priv->pix_clk, - crtc_state->adjusted_mode.clock * 1000); + crtc_state->adjusted_mode.crtc_clock * 1000); priv->update_clk_rate = false; mutex_unlock(&priv->clk_mutex); }