diff mbox series

drm/panel-simple: Fix dotclock for Ortustech COM37H3M

Message ID e63a0533ad5b5142373437ef758aedbdb716152d.1583826198.git.hns@goldelico.com (mailing list archive)
State New, archived
Headers show
Series drm/panel-simple: Fix dotclock for Ortustech COM37H3M | expand

Commit Message

H. Nikolaus Schaller March 10, 2020, 7:43 a.m. UTC
The currently listed dotclock disagrees with the currently
listed vrefresh rate. Change the dotclock to match the vrefresh.

There are two variants of the COM37H3M panel.
The older one's COM37H3M05DTC data sheet specifies:

                         MIN      TYP     MAX
CLK frequency    fCLK     --       22.4    26.3 MHz (in VGA mode)
VSYNC Frequency  fVSYNC   54       60      66   Hz
VSYNC cycle time tv       --      650      --   H
HSYNC frequency  fHSYNC   --       39.3    --   kHz
HSYNC cycle time th       --      570      --   CLK

The newer one's COM37H3M99DTC data sheet says:

                         MIN      TYP     MAX
CLK frequency    fCLK     18       19.8    27   MHz
VSYNC Frequency  fVSYNC   54       60      66   Hz
VSYNC cycle time tv      646      650     700   H
HSYNC frequency  fHSYNC  --        39.0    50.0 kHz
HSYNC cycle time th      504      508     630   CLK

So we choose a parameter set that lies within the specs
of both variants. We start at .vrefresh = 60,
choose .htotal = 570 and .vtotal = 650 and end up
in a clock of 22.230 MHz.

Reported-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/gpu/drm/panel/panel-simple.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Ville Syrjala March 10, 2020, 12:07 p.m. UTC | #1
On Tue, Mar 10, 2020 at 08:43:19AM +0100, H. Nikolaus Schaller wrote:
> The currently listed dotclock disagrees with the currently
> listed vrefresh rate. Change the dotclock to match the vrefresh.
> 
> There are two variants of the COM37H3M panel.
> The older one's COM37H3M05DTC data sheet specifies:
> 
>                          MIN      TYP     MAX
> CLK frequency    fCLK     --       22.4    26.3 MHz (in VGA mode)
> VSYNC Frequency  fVSYNC   54       60      66   Hz
> VSYNC cycle time tv       --      650      --   H
> HSYNC frequency  fHSYNC   --       39.3    --   kHz
> HSYNC cycle time th       --      570      --   CLK
> 
> The newer one's COM37H3M99DTC data sheet says:
> 
>                          MIN      TYP     MAX
> CLK frequency    fCLK     18       19.8    27   MHz
> VSYNC Frequency  fVSYNC   54       60      66   Hz
> VSYNC cycle time tv      646      650     700   H
> HSYNC frequency  fHSYNC  --        39.0    50.0 kHz
> HSYNC cycle time th      504      508     630   CLK
> 
> So we choose a parameter set that lies within the specs
> of both variants. We start at .vrefresh = 60,
> choose .htotal = 570 and .vtotal = 650 and end up
> in a clock of 22.230 MHz.
> 
> Reported-by: Ville Syrjala <ville.syrjala@linux.intel.com>
> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
> ---
>  drivers/gpu/drm/panel/panel-simple.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index e14c14ac62b5..b4cb23d4898d 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -2390,15 +2390,15 @@ static const struct panel_desc ontat_yx700wv03 = {
>  };
>  
>  static const struct drm_display_mode ortustech_com37h3m_mode  = {
> -	.clock = 22153,
> +	.clock = 22230,
>  	.hdisplay = 480,
> -	.hsync_start = 480 + 8,
> -	.hsync_end = 480 + 8 + 10,
> -	.htotal = 480 + 8 + 10 + 10,
> +	.hsync_start = 480 + 40,
> +	.hsync_end = 480 + 40 + 10,
> +	.htotal = 480 + 40 + 10 + 40,
>  	.vdisplay = 640,
>  	.vsync_start = 640 + 4,
> -	.vsync_end = 640 + 4 + 3,
> -	.vtotal = 640 + 4 + 3 + 4,
> +	.vsync_end = 640 + 4 + 2,
> +	.vtotal = 640 + 4 + 2 + 4,
>  	.vrefresh = 60,

Numbers look consistent.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

>  	.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
>  };
> -- 
> 2.23.0
Sam Ravnborg March 10, 2020, 5:43 p.m. UTC | #2
Hi Nikolaus

Thanks for the detailed explanation.

Applied and pushed to drm-misc-next.

	Sam

On Tue, Mar 10, 2020 at 08:43:19AM +0100, H. Nikolaus Schaller wrote:
> The currently listed dotclock disagrees with the currently
> listed vrefresh rate. Change the dotclock to match the vrefresh.
> 
> There are two variants of the COM37H3M panel.
> The older one's COM37H3M05DTC data sheet specifies:
> 
>                          MIN      TYP     MAX
> CLK frequency    fCLK     --       22.4    26.3 MHz (in VGA mode)
> VSYNC Frequency  fVSYNC   54       60      66   Hz
> VSYNC cycle time tv       --      650      --   H
> HSYNC frequency  fHSYNC   --       39.3    --   kHz
> HSYNC cycle time th       --      570      --   CLK
> 
> The newer one's COM37H3M99DTC data sheet says:
> 
>                          MIN      TYP     MAX
> CLK frequency    fCLK     18       19.8    27   MHz
> VSYNC Frequency  fVSYNC   54       60      66   Hz
> VSYNC cycle time tv      646      650     700   H
> HSYNC frequency  fHSYNC  --        39.0    50.0 kHz
> HSYNC cycle time th      504      508     630   CLK
> 
> So we choose a parameter set that lies within the specs
> of both variants. We start at .vrefresh = 60,
> choose .htotal = 570 and .vtotal = 650 and end up
> in a clock of 22.230 MHz.
> 
> Reported-by: Ville Syrjala <ville.syrjala@linux.intel.com>
> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
> ---
>  drivers/gpu/drm/panel/panel-simple.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index e14c14ac62b5..b4cb23d4898d 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -2390,15 +2390,15 @@ static const struct panel_desc ontat_yx700wv03 = {
>  };
>  
>  static const struct drm_display_mode ortustech_com37h3m_mode  = {
> -	.clock = 22153,
> +	.clock = 22230,
>  	.hdisplay = 480,
> -	.hsync_start = 480 + 8,
> -	.hsync_end = 480 + 8 + 10,
> -	.htotal = 480 + 8 + 10 + 10,
> +	.hsync_start = 480 + 40,
> +	.hsync_end = 480 + 40 + 10,
> +	.htotal = 480 + 40 + 10 + 40,
>  	.vdisplay = 640,
>  	.vsync_start = 640 + 4,
> -	.vsync_end = 640 + 4 + 3,
> -	.vtotal = 640 + 4 + 3 + 4,
> +	.vsync_end = 640 + 4 + 2,
> +	.vtotal = 640 + 4 + 2 + 4,
>  	.vrefresh = 60,
>  	.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
>  };
> -- 
> 2.23.0
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff mbox series

Patch

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index e14c14ac62b5..b4cb23d4898d 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -2390,15 +2390,15 @@  static const struct panel_desc ontat_yx700wv03 = {
 };
 
 static const struct drm_display_mode ortustech_com37h3m_mode  = {
-	.clock = 22153,
+	.clock = 22230,
 	.hdisplay = 480,
-	.hsync_start = 480 + 8,
-	.hsync_end = 480 + 8 + 10,
-	.htotal = 480 + 8 + 10 + 10,
+	.hsync_start = 480 + 40,
+	.hsync_end = 480 + 40 + 10,
+	.htotal = 480 + 40 + 10 + 40,
 	.vdisplay = 640,
 	.vsync_start = 640 + 4,
-	.vsync_end = 640 + 4 + 3,
-	.vtotal = 640 + 4 + 3 + 4,
+	.vsync_end = 640 + 4 + 2,
+	.vtotal = 640 + 4 + 2 + 4,
 	.vrefresh = 60,
 	.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
 };