openwrt/target/linux/bcm27xx/patches-5.4/950-0267-drm-vc4-Limit-fkms-to-modes-85Hz.patch
Álvaro Fernández Rojas a1383655cf bcm27xx: add linux 5.4 support
Tested on bcm2710 (Raspberry Pi 3B).

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2020-02-29 12:50:51 +01:00

27 lines
863 B
Diff

From 9f9d67a11cfd6318d2bd1321090c0950242cfa25 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
Date: Tue, 18 Jun 2019 21:37:45 +0100
Subject: [PATCH] drm/vc4: Limit fkms to modes <= 85Hz
Selecting 1080p100 and 120 has very limited gain, but don't want
to block VGA85 and similar.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
---
drivers/gpu/drm/vc4/vc4_firmware_kms.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
@@ -823,6 +823,10 @@ vc4_crtc_mode_valid(struct drm_crtc *crt
return MODE_NO_DBLESCAN;
}
+ /* Disable refresh rates > 85Hz as limited gain from them */
+ if (drm_mode_vrefresh(mode) > 85)
+ return MODE_BAD_VVALUE;
+
/* Limit the pixel clock based on the HDMI clock limits from the
* firmware
*/