From fd1d9e2d4382674f421bab003f9a64cc27b003f4 Mon Sep 17 00:00:00 2001
From: Dario Binacchi <dariobin@libero.it>
Date: Mon, 22 Mar 2021 22:33:36 +0100
Subject: drm/tilcdc: fix LCD pixel clock setting
The tilcdc_pclk_diff() compares the requested pixel clock rate to the
real one, so passing it clk_rate instead of clk_rate / clkdiv caused
it to fail even if the clk_rate was properly set. Adding the
real_pclk_rate variable makes the code more readable.
Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Jyri Sarha <jyri.sarha@iki.fi>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Jyri Sarha <jyri.sarha@iki.fi>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322213337.26667-3-dariobin@libero.it
---
drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
(limited to 'drivers/gpu/drm/tilcdc')
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index 3d0b7fbae02d..25278f59d165 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -203,7 +203,7 @@ static void tilcdc_crtc_set_clk(struct drm_crtc *crtc)
struct drm_device *dev = crtc->dev;
struct tilcdc_drm_private *priv = dev->dev_private;
struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
- unsigned long clk_rate, real_rate, pclk_rate;
+ unsigned long clk_rate, real_rate, real_pclk_rate, pclk_rate;
unsigned int clkdiv;
int ret;
@@ -214,7 +214,8 @@ static void tilcdc_crtc_set_clk(struct drm_crtc *crtc)
ret = clk_set_rate(priv->clk, pclk_rate * clkdiv);
clk_rate = clk_get_rate(priv->clk);
- if (ret < 0 || tilcdc_pclk_diff(pclk_rate, clk_rate) > 5) {
+ real_pclk_rate = clk_rate / clkdiv;
+ if (ret < 0 || tilcdc_pclk_diff(pclk_rate, real_pclk_rate) > 5) {
/*
* If we fail to set the clock rate (some architectures don't
* use the common clock framework yet and may not implement
--
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