diff mbox series

[27/33] drm/panel-simple: Fix dotclock for Sharp LQ035Q7DB03

Message ID 20200302203452.17977-28-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series drm/panel: Fix dotclocks | expand

Commit Message

Ville Syrjälä March 2, 2020, 8:34 p.m. UTC
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

The currently listed dotclock disagrees with the currently
listed vrefresh rate. Change the dotclock to match the vrefresh.

Someone tell me which (if either) of the dotclock or vreresh is
correct?

Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/panel/panel-simple.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Vladimir Zapolskiy March 2, 2020, 9:40 p.m. UTC | #1
Hi Ville,

On 3/2/20 10:34 PM, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> The currently listed dotclock disagrees with the currently
> listed vrefresh rate. Change the dotclock to match the vrefresh.
> 
> Someone tell me which (if either) of the dotclock or vreresh is
> correct?

yes, I will tell you, see my answer below.

Adding Linus as a person who may be interested in PL111 specifics.

> Cc: Vladimir Zapolskiy <vz@mleia.com>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Thierry Reding <treding@nvidia.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/panel/panel-simple.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index 3012b47c1e4e..7526af2d6d95 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -2949,7 +2949,7 @@ static const struct panel_desc sharp_lq070y3dg3b = {
>  };
>  
>  static const struct drm_display_mode sharp_lq035q7db03_mode = {
> -	.clock = 5500,
> +	.clock = 5419,
>  	.hdisplay = 240,
>  	.hsync_start = 240 + 16,
>  	.hsync_end = 240 + 16 + 7,
> 

Here .clock is correct, you may find the usage of the panel in
lpc3250-phy3250.dts example, and the PL111 controller on the SoC
won't be able to provide the exactly computed `.clock = 5419'.

So, I have to NAK this change, in this example the difference
between the declared and the computed .vreresh is one Hz, which
I hope can be accepted as negligible and ignorable, otherwise,
if you insist, please correct the .vrefresh from 60 to 61.

--
Best wishes,
Vladimir
Ville Syrjälä March 3, 2020, 2:49 p.m. UTC | #2
On Mon, Mar 02, 2020 at 11:40:07PM +0200, Vladimir Zapolskiy wrote:
> Hi Ville,
> 
> On 3/2/20 10:34 PM, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > The currently listed dotclock disagrees with the currently
> > listed vrefresh rate. Change the dotclock to match the vrefresh.
> > 
> > Someone tell me which (if either) of the dotclock or vreresh is
> > correct?
> 
> yes, I will tell you, see my answer below.
> 
> Adding Linus as a person who may be interested in PL111 specifics.
> 
> > Cc: Vladimir Zapolskiy <vz@mleia.com>
> > Cc: Rob Herring <robh@kernel.org>
> > Cc: Thierry Reding <treding@nvidia.com>
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/panel/panel-simple.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> > index 3012b47c1e4e..7526af2d6d95 100644
> > --- a/drivers/gpu/drm/panel/panel-simple.c
> > +++ b/drivers/gpu/drm/panel/panel-simple.c
> > @@ -2949,7 +2949,7 @@ static const struct panel_desc sharp_lq070y3dg3b = {
> >  };
> >  
> >  static const struct drm_display_mode sharp_lq035q7db03_mode = {
> > -	.clock = 5500,
> > +	.clock = 5419,
> >  	.hdisplay = 240,
> >  	.hsync_start = 240 + 16,
> >  	.hsync_end = 240 + 16 + 7,
> > 
> 
> Here .clock is correct, you may find the usage of the panel in
> lpc3250-phy3250.dts example, and the PL111 controller on the SoC
> won't be able to provide the exactly computed `.clock = 5419'.

OK, I'll drop this one.

> 
> So, I have to NAK this change, in this example the difference
> between the declared and the computed .vreresh is one Hz, which
> I hope can be accepted as negligible and ignorable, otherwise,
> if you insist, please correct the .vrefresh from 60 to 61.

I'm going to nuke .vrefresh entirely.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 3012b47c1e4e..7526af2d6d95 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -2949,7 +2949,7 @@  static const struct panel_desc sharp_lq070y3dg3b = {
 };
 
 static const struct drm_display_mode sharp_lq035q7db03_mode = {
-	.clock = 5500,
+	.clock = 5419,
 	.hdisplay = 240,
 	.hsync_start = 240 + 16,
 	.hsync_end = 240 + 16 + 7,