diff mbox

[v3,05/11] drm/i915: SDVO pixel clock check

Message ID 1438344840-3490-6-git-send-email-mika.kahola@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mika Kahola July 31, 2015, 12:13 p.m. UTC
It is possible the we request to have a mode that has
higher pixel clock than our HW can support. This patch
checks if requested pixel clock is lower than the one
supported by the HW. The requested mode is discarded
if we cannot support the requested pixel clock.

This patch applies to SDVO.

V2:
- removed computation for max pixel clock

V3:
- cleanup by removing unnecessary lines

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
---
 drivers/gpu/drm/i915/intel_sdvo.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Ville Syrjälä Aug. 12, 2015, 5:46 p.m. UTC | #1
On Fri, Jul 31, 2015 at 03:13:54PM +0300, Mika Kahola wrote:
> It is possible the we request to have a mode that has
> higher pixel clock than our HW can support. This patch
> checks if requested pixel clock is lower than the one
> supported by the HW. The requested mode is discarded
> if we cannot support the requested pixel clock.
> 
> This patch applies to SDVO.
> 
> V2:
> - removed computation for max pixel clock
> 
> V3:
> - cleanup by removing unnecessary lines
> 
> Signed-off-by: Mika Kahola <mika.kahola@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_sdvo.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
> index 2c435a7..55a2853 100644
> --- a/drivers/gpu/drm/i915/intel_sdvo.c
> +++ b/drivers/gpu/drm/i915/intel_sdvo.c
> @@ -1560,6 +1560,7 @@ intel_sdvo_mode_valid(struct drm_connector *connector,
>  		      struct drm_display_mode *mode)
>  {
>  	struct intel_sdvo *intel_sdvo = intel_attached_sdvo(connector);
> +	int max_pixclk = to_i915(connector->dev)->max_dotclk;
>  
>  	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
>  		return MODE_NO_DBLESCAN;
> @@ -1570,6 +1571,9 @@ intel_sdvo_mode_valid(struct drm_connector *connector,
>  	if (intel_sdvo->pixel_clock_max < mode->clock)
>  		return MODE_CLOCK_HIGH;
>  
> +	if (mode->clock > max_pixclk)
> +		return MODE_CLOCK_HIGH;
> +

Had to think a bit on this one. But yeah checking mode->clock is the
right thing. I suppose in theory we should do the whole
intel_sdvo_get_preferred_input_mode() thing here, but I guess that would
clobber the current sdvo device state and so can't be done safely.

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

>  	if (intel_sdvo->is_lvds) {
>  		if (mode->hdisplay > intel_sdvo->sdvo_lvds_fixed_mode->hdisplay)
>  			return MODE_PANEL;
> -- 
> 1.9.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 2c435a7..55a2853 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1560,6 +1560,7 @@  intel_sdvo_mode_valid(struct drm_connector *connector,
 		      struct drm_display_mode *mode)
 {
 	struct intel_sdvo *intel_sdvo = intel_attached_sdvo(connector);
+	int max_pixclk = to_i915(connector->dev)->max_dotclk;
 
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;
@@ -1570,6 +1571,9 @@  intel_sdvo_mode_valid(struct drm_connector *connector,
 	if (intel_sdvo->pixel_clock_max < mode->clock)
 		return MODE_CLOCK_HIGH;
 
+	if (mode->clock > max_pixclk)
+		return MODE_CLOCK_HIGH;
+
 	if (intel_sdvo->is_lvds) {
 		if (mode->hdisplay > intel_sdvo->sdvo_lvds_fixed_mode->hdisplay)
 			return MODE_PANEL;