| Message ID | 20170627195839.3338-4-eric@anholt.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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; >
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); + adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal; adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal;
I'm not sure what changed where I started getting vrefresh=0 from the mode to be fixed up. Signed-off-by: Eric Anholt <eric@anholt.net> --- drivers/gpu/drm/vc4/vc4_dsi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)