On 27.06.2017 21:58, Eric Anholt wrote:
I'm not sure what changed where I started getting vrefresh=0 from the mode to be fixed up.
It can be a case of low pixel_clock value, maybe it should be investigated further, unless there is execution path with forgotten mode->vrefresh =
drm_mode_vrefresh(mode)
Signed-off-by: Eric Anholt eric@anholt.net
drivers/gpu/drm/vc4/vc4_dsi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index 629d372633e6..fca4d7fd677e 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -866,7 +866,9 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder, adjusted_mode->clock = pixel_clock_hz / 1000 + 1;
/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
- adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal);
- adjusted_mode->htotal = pixel_clock_hz / (drm_mode_vrefresh(mode) *
mode->vtotal);
I am not sure but I guess division by zero is also possible here. I do not know if you need to handle interlaced/dblscan/vscan modes, but maybe it would be safer to calculate adjusted_htotal according to:
adjusted_mode->htotal = pixel_clock_hz * mode->htotal / (mode->clock * 1000)
or sth similar.
Regards Andrzej
adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal; adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal;