[Intel-gfx] [PATCH v3] drm/i915: Fake HDMI live status

[Ville Syrjälä]

On Thu, Apr 21, 2016 at 04:48:32PM +0530, Shashank Sharma wrote:
> This patch does the following:
> - Fakes live status of HDMI as connected (even if that's not).
>   While testing certain (monitor + cable) combinations with
>   various intel  platforms, it seems that live status register
>   doesn't work reliably on some older devices. So limit the
>   live_status check for HDMI detection, only for platforms
>   from gen7 onwards.
> 
> Fixes: 237ed86c693d ("drm/i915: Check live status before reading edid")
> Cc: stable at vger.kernel.org # v4.4
> 
> V2: restrict faking live_status to certain platforms
> V3: (Ville)
>    - keep the debug message for !live_status case
>    - fix indentation of comment
>    - remove "warning" from the debug message
> 
>     (Jani)
>    - Change format of fix details in the commit message
> 
> Suggested-by: Ville Syrjala <ville.syrjala at linux.intel.com>
> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>

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

> ---
>  drivers/gpu/drm/i915/intel_hdmi.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> index b199ede..2cdab73 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1412,8 +1412,16 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
>  				hdmi_to_dig_port(intel_hdmi));
>  	}
>  
> -	if (!live_status)
> -		DRM_DEBUG_KMS("Live status not up!");
> +	if (!live_status) {
> +		DRM_DEBUG_KMS("HDMI live status down\n");
> +		/*
> +		 * Live status register is not reliable on all intel platforms.
> +		 * So consider live_status only for certain platforms, for
> +		 * others, read EDID to determine presence of sink.
> +		 */
> +		if (INTEL_INFO(dev_priv)->gen < 7 || IS_IVYBRIDGE(dev_priv))
> +			live_status = true;
> +	}
>  
>  	intel_hdmi_unset_edid(connector);
>  
> -- 
> 1.9.1

-- 
Ville Syrjälä
Intel OTC