| Message ID | 20241005143818.2036-1-jonathan@marek.ca (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] drm/msm/dsi: improve/fix dsc pclk calculation | expand |
On 5.10.2024 4:38 PM, Jonathan Marek wrote: > drm_mode_vrefresh() can introduce a large rounding error, avoid it. > > Signed-off-by: Jonathan Marek <jonathan@marek.ca> > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c > index 185d7de0bf376..1205aa398e445 100644 > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c > @@ -542,7 +542,7 @@ static unsigned long dsi_adjust_pclk_for_compression(const struct drm_display_mo > > int new_htotal = mode->htotal - mode->hdisplay + new_hdisplay; > > - return new_htotal * mode->vtotal * drm_mode_vrefresh(mode); > + return mult_frac(mode->clock * 1000u, new_htotal, mode->htotal); This seems to ignore mult/div by two on certain mode flags.. is that intended? Konrad
On 10/5/24 12:31 PM, Konrad Dybcio wrote: > On 5.10.2024 4:38 PM, Jonathan Marek wrote: >> drm_mode_vrefresh() can introduce a large rounding error, avoid it. >> >> Signed-off-by: Jonathan Marek <jonathan@marek.ca> >> --- >> drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c >> index 185d7de0bf376..1205aa398e445 100644 >> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c >> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c >> @@ -542,7 +542,7 @@ static unsigned long dsi_adjust_pclk_for_compression(const struct drm_display_mo >> >> int new_htotal = mode->htotal - mode->hdisplay + new_hdisplay; >> >> - return new_htotal * mode->vtotal * drm_mode_vrefresh(mode); >> + return mult_frac(mode->clock * 1000u, new_htotal, mode->htotal); > > This seems to ignore mult/div by two on certain mode flags.. is that > intended? > > Konrad > It is intended - those flags are not relevant to DSI panels, and DSC pclk adjustment is only about how DSC affects htotal.
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 185d7de0bf376..1205aa398e445 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -542,7 +542,7 @@ static unsigned long dsi_adjust_pclk_for_compression(const struct drm_display_mo int new_htotal = mode->htotal - mode->hdisplay + new_hdisplay; - return new_htotal * mode->vtotal * drm_mode_vrefresh(mode); + return mult_frac(mode->clock * 1000u, new_htotal, mode->htotal); } static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode,
drm_mode_vrefresh() can introduce a large rounding error, avoid it. Signed-off-by: Jonathan Marek <jonathan@marek.ca> --- drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)