[Intel-gfx] [PATCH 3/9] drm/i915: PCH_NOP

[Daniel Vetter]

On Wed, Mar 13, 2013 at 11:21:02AM -0700, Ben Widawsky wrote:
> Given certain fusing options discussed in the previous patch, it's
> possible to end up with platforms that normally have PCH but that PCH
> doesn't actually exist. In many cases, this is easily remedied with
> setting 0 pipes. This covers the other corners.
> 
> Requiring this is a symptom of improper code splitting (using
> HAS_PCH_SPLIT instead of proper GEN checking, basically). I do not want
> to fix this.
> 
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
>  drivers/gpu/drm/i915/i915_drv.h      | 2 ++
>  drivers/gpu/drm/i915/intel_display.c | 4 +++-
>  drivers/gpu/drm/i915/intel_lvds.c    | 4 ++++
>  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 587dca0..ceed199 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -461,6 +461,7 @@ enum intel_pch {
>  	PCH_IBX,	/* Ibexpeak PCH */
>  	PCH_CPT,	/* Cougarpoint PCH */
>  	PCH_LPT,	/* Lynxpoint PCH */
> +	PCH_NOP,
>  };
>  
>  enum intel_sbi_destination {
> @@ -1351,6 +1352,7 @@ struct drm_i915_file_private {
>  #define HAS_PCH_LPT(dev) (INTEL_PCH_TYPE(dev) == PCH_LPT)
>  #define HAS_PCH_CPT(dev) (INTEL_PCH_TYPE(dev) == PCH_CPT)
>  #define HAS_PCH_IBX(dev) (INTEL_PCH_TYPE(dev) == PCH_IBX)
> +#define HAS_PCH_NOP(dev) (INTEL_PCH_TYPE(dev) == PCH_NOP)
>  #define HAS_PCH_SPLIT(dev) (INTEL_PCH_TYPE(dev) != PCH_NONE)
>  
>  #define HAS_FORCE_WAKE(dev) (INTEL_INFO(dev)->has_force_wake)
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index d6dbffd..1f0624e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -5085,7 +5085,9 @@ static void lpt_init_pch_refclk(struct drm_device *dev)
>   */
>  void intel_init_pch_refclk(struct drm_device *dev)
>  {

Since this function here only deals with display refclocks I think a
num_pipes == 0 check should equally work. And also makes it clear what's
exactly going on.

> -	if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
> +	if (HAS_PCH_NOP(dev))
> +		return;
> +	else if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
>  		ironlake_init_pch_refclk(dev);
>  	else if (HAS_PCH_LPT(dev))
>  		lpt_init_pch_refclk(dev);
> diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
> index 6b24fc5..613ac43 100644
> --- a/drivers/gpu/drm/i915/intel_lvds.c
> +++ b/drivers/gpu/drm/i915/intel_lvds.c
> @@ -1018,6 +1018,10 @@ static bool compute_is_dual_link_lvds(struct intel_lvds_encoder *lvds_encoder)
>  
>  static bool intel_lvds_supported(struct drm_device *dev)
>  {
> +
> +	if (HAS_PCH_NOP(dev))
> +		return false;

This hunk here looks superflous, imo we should stop any and all output
probing much earlier in the callchain.
-Daniel

> +
>  	/* With the introduction of the PCH we gained a dedicated
>  	 * LVDS presence pin, use it. */
>  	if (HAS_PCH_SPLIT(dev))
> -- 
> 1.8.1.5
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch