From a0695cf550835a455357677ba53f95223cd3d66d Mon Sep 17 00:00:00 2001
From: Claudiu Beznea <claudiu.beznea@microchip.com>
Date: Wed, 18 Dec 2019 14:28:24 +0200
Subject: drm: atmel-hlcdc: use double rate for pixel clock only if supported
Git-commit: 07acf4bafe81dd37eff3fbcfbbdbc48084bc202b
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

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@microchip.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: <stable@vger.kernel.org> # v5.3+
Link: https://patchwork.freedesktop.org/patch/msgid/1576672109-22707-2-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index f2e73e6d46b8..5040ed8d0871 100644
--- 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_nofb(struct drm_crtc *c)
 		     (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;
-- 
2.28.0