Working with HDMI TVs is a real pain as they tend to overscan by default, meaning that the pixels around the edge of the framebuffer are not displayed. This is well explained here: http://mjg59.dreamwidth.org/8705.html
There is a bit in the HDMI info frame that can request that the remote display shows the full pixel data ("underscan"). For the remote display, the HDMI spec states that this is optional - it doesn't have to listen. That means that most TVs will probably ignore this.
But, maybe there are a handful of TVs for which this would help the situation. As we live in a digital world, ask the remote display not to overscan by default.
Signed-off-by: Daniel Drake drake@endlessm.com --- drivers/gpu/drm/drm_edid.c | 1 + 1 file changed, 1 insertion(+)
Replaces the patch titled "video: hdmi: request underscan by default" This version moves the change to the DRM layer, as requested by Ville Syrjälä.
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index b924306..f8d8a1d 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -3599,6 +3599,7 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
frame->picture_aspect = HDMI_PICTURE_ASPECT_NONE; frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE; + frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
return 0; }
On Thu, Feb 27, 2014 at 09:19:30AM -0600, Daniel Drake wrote:
Working with HDMI TVs is a real pain as they tend to overscan by default, meaning that the pixels around the edge of the framebuffer are not displayed. This is well explained here: http://mjg59.dreamwidth.org/8705.html
There is a bit in the HDMI info frame that can request that the remote display shows the full pixel data ("underscan"). For the remote display, the HDMI spec states that this is optional - it doesn't have to listen. That means that most TVs will probably ignore this.
But, maybe there are a handful of TVs for which this would help the situation. As we live in a digital world, ask the remote display not to overscan by default.
Signed-off-by: Daniel Drake drake@endlessm.com
Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com
drivers/gpu/drm/drm_edid.c | 1 + 1 file changed, 1 insertion(+)
Replaces the patch titled "video: hdmi: request underscan by default" This version moves the change to the DRM layer, as requested by Ville Syrjälä.
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index b924306..f8d8a1d 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -3599,6 +3599,7 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
frame->picture_aspect = HDMI_PICTURE_ASPECT_NONE; frame->active_aspect = HDMI_ACTIVE_ASPECT_PICTURE;
frame->scan_mode = HDMI_SCAN_MODE_UNDERSCAN;
return 0;
}
1.8.3.2
On Thu, Feb 27, 2014 at 05:42:36PM +0200, Ville Syrjälä wrote:
On Thu, Feb 27, 2014 at 09:19:30AM -0600, Daniel Drake wrote:
Working with HDMI TVs is a real pain as they tend to overscan by default, meaning that the pixels around the edge of the framebuffer are not displayed. This is well explained here: http://mjg59.dreamwidth.org/8705.html
There is a bit in the HDMI info frame that can request that the remote display shows the full pixel data ("underscan"). For the remote display, the HDMI spec states that this is optional - it doesn't have to listen. That means that most TVs will probably ignore this.
But, maybe there are a handful of TVs for which this would help the situation. As we live in a digital world, ask the remote display not to overscan by default.
Signed-off-by: Daniel Drake drake@endlessm.com
Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com
As a small note, I never managed to find a TV (out of the 2 I have around) that honour that flag, which is why I haven't pushed that patch before. I also had the hope that we could automatically overscan with the right amount at some point (with some sort of database) and with that flag set, we don't know if the sink is overscanning or not, but then I guess we could include whether the TV honour in that flag in a db as well.
In any case, I echo the review:
Reviewed-by: Damien Lespiau damien.lespiau@intel.com
On Thu, Feb 27, 2014 at 03:49:10PM +0000, Damien Lespiau wrote:
On Thu, Feb 27, 2014 at 05:42:36PM +0200, Ville Syrjälä wrote:
On Thu, Feb 27, 2014 at 09:19:30AM -0600, Daniel Drake wrote:
Working with HDMI TVs is a real pain as they tend to overscan by default, meaning that the pixels around the edge of the framebuffer are not displayed. This is well explained here: http://mjg59.dreamwidth.org/8705.html
There is a bit in the HDMI info frame that can request that the remote display shows the full pixel data ("underscan"). For the remote display, the HDMI spec states that this is optional - it doesn't have to listen. That means that most TVs will probably ignore this.
But, maybe there are a handful of TVs for which this would help the situation. As we live in a digital world, ask the remote display not to overscan by default.
Signed-off-by: Daniel Drake drake@endlessm.com
Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com
As a small note, I never managed to find a TV (out of the 2 I have around) that honour that flag, which is why I haven't pushed that patch before. I also had the hope that we could automatically overscan with the right amount at some point (with some sort of database) and with that flag set, we don't know if the sink is overscanning or not, but then I guess we could include whether the TV honour in that flag in a db as well.
In any case, I echo the review:
Reviewed-by: Damien Lespiau damien.lespiau@intel.com
Applied to my topic/core-stuff grab-bag branch, thanks for patch&review. -Daniel
dri-devel@lists.freedesktop.org
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Damien Lespiau -
Daniel Drake -
Daniel Vetter -
Ville Syrjälä