1 From 06a0e398e7dcd6ba0a61713596c32ec6d43b47c8 Mon Sep 17 00:00:00 2001
2 From: Dave Stevenson <dave.stevenson@raspberrypi.org>
3 Date: Tue, 18 Jun 2019 21:37:45 +0100
4 Subject: [PATCH] drm/vc4: Limit fkms to modes <= 85Hz
6 Selecting 1080p100 and 120 has very limited gain, but don't want
7 to block VGA85 and similar.
9 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
11 drivers/gpu/drm/vc4/vc4_firmware_kms.c | 4 ++++
12 1 file changed, 4 insertions(+)
14 --- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c
15 +++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
16 @@ -822,6 +822,10 @@ vc4_crtc_mode_valid(struct drm_crtc *crt
17 return MODE_NO_DBLESCAN;
20 + /* Disable refresh rates > 85Hz as limited gain from them */
21 + if (drm_mode_vrefresh(mode) > 85)
22 + return MODE_BAD_VVALUE;
24 /* Limit the pixel clock based on the HDMI clock limits from the