[Intel-gfx] [PATCH] drm/i915: Fix hpd live status bits for g4x

[Daniel Vetter]

On Wed, Feb 10, 2016 at 07:59:05PM +0200, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Looks like g4x hpd live status bits actually agree with the spec. At
> least they do on the machine I have, and apparently on Nick Bowler's
> g4x as well.
> 
> So gm45 may be the only platform where they don't agree. At least
> that seems to be the case based on the (somewhat incomplete)
> logs/dumps in [1], and Daniel has also tested this on his gm45
> sometime in the past.
> 
> So let's change the bits to match the spec on g4x. That actually makes
> the g4x bits identical to vlv/chv so we can just share the code
> between those platforms, leaving gm45 as the special case.
> 
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=52361
> 
> Cc: Shashank Sharma <shashank.sharma at intel.com>
> Cc: Sonika Jindal <sonika.jindal at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Nick Bowler <nbowler at draconx.ca>
> References: https://lists.freedesktop.org/archives/dri-devel/2016-February/100382.html
> Reported-by: Nick Bowler <nbowler at draconx.ca>
> Cc: stable at vger.kernel.org
> Fixes: 237ed86c693d ("drm/i915: Check live status before reading edid")
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Yeah I'm hopeful this will work. Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Since CI is down and this is super restricted impact and fixing a
regression I'm voting that we'll pick it up right away. Jani, are you ok
with that?
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_reg.h | 15 ++++++++-------
>  drivers/gpu/drm/i915/intel_dp.c | 14 +++++++-------
>  2 files changed, 15 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 188ad5de020f..678faa957e75 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3296,19 +3296,20 @@ enum skl_disp_power_wells {
>  
>  #define PORT_HOTPLUG_STAT	_MMIO(dev_priv->info.display_mmio_offset + 0x61114)
>  /*
> - * HDMI/DP bits are gen4+
> + * HDMI/DP bits are g4x+
>   *
>   * WARNING: Bspec for hpd status bits on gen4 seems to be completely confused.
>   * Please check the detailed lore in the commit message for for experimental
>   * evidence.
>   */
> -#define   PORTD_HOTPLUG_LIVE_STATUS_G4X		(1 << 29)
> +/* Bspec says GM45 should match G4X/VLV/CHV, but reality disagrees */
> +#define   PORTD_HOTPLUG_LIVE_STATUS_GM45	(1 << 29)
> +#define   PORTC_HOTPLUG_LIVE_STATUS_GM45	(1 << 28)
> +#define   PORTB_HOTPLUG_LIVE_STATUS_GM45	(1 << 27)
> +/* G4X/VLV/CHV DP/HDMI bits again match Bspec */
> +#define   PORTD_HOTPLUG_LIVE_STATUS_G4X		(1 << 27)
>  #define   PORTC_HOTPLUG_LIVE_STATUS_G4X		(1 << 28)
> -#define   PORTB_HOTPLUG_LIVE_STATUS_G4X		(1 << 27)
> -/* VLV DP/HDMI bits again match Bspec */
> -#define   PORTD_HOTPLUG_LIVE_STATUS_VLV		(1 << 27)
> -#define   PORTC_HOTPLUG_LIVE_STATUS_VLV		(1 << 28)
> -#define   PORTB_HOTPLUG_LIVE_STATUS_VLV		(1 << 29)
> +#define   PORTB_HOTPLUG_LIVE_STATUS_G4X		(1 << 29)
>  #define   PORTD_HOTPLUG_INT_STATUS		(3 << 21)
>  #define   PORTD_HOTPLUG_INT_LONG_PULSE		(2 << 21)
>  #define   PORTD_HOTPLUG_INT_SHORT_PULSE		(1 << 21)
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index a073f04a5330..bbe18996efe6 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -4490,20 +4490,20 @@ static bool g4x_digital_port_connected(struct drm_i915_private *dev_priv,
>  	return I915_READ(PORT_HOTPLUG_STAT) & bit;
>  }
>  
> -static bool vlv_digital_port_connected(struct drm_i915_private *dev_priv,
> -				       struct intel_digital_port *port)
> +static bool gm45_digital_port_connected(struct drm_i915_private *dev_priv,
> +					struct intel_digital_port *port)
>  {
>  	u32 bit;
>  
>  	switch (port->port) {
>  	case PORT_B:
> -		bit = PORTB_HOTPLUG_LIVE_STATUS_VLV;
> +		bit = PORTB_HOTPLUG_LIVE_STATUS_GM45;
>  		break;
>  	case PORT_C:
> -		bit = PORTC_HOTPLUG_LIVE_STATUS_VLV;
> +		bit = PORTC_HOTPLUG_LIVE_STATUS_GM45;
>  		break;
>  	case PORT_D:
> -		bit = PORTD_HOTPLUG_LIVE_STATUS_VLV;
> +		bit = PORTD_HOTPLUG_LIVE_STATUS_GM45;
>  		break;
>  	default:
>  		MISSING_CASE(port->port);
> @@ -4555,8 +4555,8 @@ bool intel_digital_port_connected(struct drm_i915_private *dev_priv,
>  		return cpt_digital_port_connected(dev_priv, port);
>  	else if (IS_BROXTON(dev_priv))
>  		return bxt_digital_port_connected(dev_priv, port);
> -	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> -		return vlv_digital_port_connected(dev_priv, port);
> +	else if (IS_GM45(dev_priv))
> +		return gm45_digital_port_connected(dev_priv, port);
>  	else
>  		return g4x_digital_port_connected(dev_priv, port);
>  }
> -- 
> 2.4.10
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch