[PATCH 5.4 186/309] drm: atmel-hlcdc: use double rate for pixel clock only if supported
From: Greg Kroah-Hartman
Date: Mon Feb 10 2020 - 08:16:56 EST
From: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
commit 07acf4bafe81dd37eff3fbcfbbdbc48084bc202b upstream.
Doubled system clock should be used as pixel cock source only if this
is supported. This is emphasized by the value of
atmel_hlcdc_crtc::dc::desc::fixed_clksrc.
Fixes: a6eca2abdd42 ("drm: atmel-hlcdc: add config option for clock selection")
Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
Signed-off-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Boris Brezillon <bbrezillon@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v5.3+
Link: https://patchwork.freedesktop.org/patch/msgid/1576672109-22707-2-git-send-email-claudiu.beznea@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -95,14 +95,14 @@ static void atmel_hlcdc_crtc_mode_set_no
(adj->crtc_hdisplay - 1) |
((adj->crtc_vdisplay - 1) << 16));
+ prate = clk_get_rate(crtc->dc->hlcdc->sys_clk);
+ mode_rate = adj->crtc_clock * 1000;
if (!crtc->dc->desc->fixed_clksrc) {
+ prate *= 2;
cfg |= ATMEL_HLCDC_CLKSEL;
mask |= ATMEL_HLCDC_CLKSEL;
}
- prate = 2 * clk_get_rate(crtc->dc->hlcdc->sys_clk);
- mode_rate = adj->crtc_clock * 1000;
-
div = DIV_ROUND_UP(prate, mode_rate);
if (div < 2) {
div = 2;