Re: [PATCH 02/10] drm/i915/display: change probe for no display case

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, May 22, 2024 at 08:33:39PM +0300, Jani Nikula wrote:
> Return NULL for errors, and handle the no display case in one
> location. This will make subsequent changes easier.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  .../drm/i915/display/intel_display_device.c    | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index 9edadc7270f6..03181bb79d21 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -881,7 +881,7 @@ probe_gmdid_display(struct drm_i915_private *i915, u16 *ver, u16 *rel, u16 *step
>  	addr = pci_iomap_range(pdev, 0, i915_mmio_reg_offset(GMD_ID_DISPLAY), sizeof(u32));
>  	if (!addr) {
>  		drm_err(&i915->drm, "Cannot map MMIO BAR to read display GMD_ID\n");
> -		return &no_display;
> +		return NULL;
>  	}
>  
>  	val = ioread32(addr);
> @@ -889,7 +889,7 @@ probe_gmdid_display(struct drm_i915_private *i915, u16 *ver, u16 *rel, u16 *step
>  
>  	if (val == 0) {
>  		drm_dbg_kms(&i915->drm, "Device doesn't have display\n");
> -		return &no_display;
> +		return NULL;
>  	}
>  
>  	*ver = REG_FIELD_GET(GMD_ID_ARCH_MASK, val);
> @@ -903,7 +903,7 @@ probe_gmdid_display(struct drm_i915_private *i915, u16 *ver, u16 *rel, u16 *step
>  
>  	drm_err(&i915->drm, "Unrecognized display IP version %d.%02d; disabling display.\n",
>  		*ver, *rel);
> -	return &no_display;
> +	return NULL;
>  }
>  
>  static const struct intel_display_device_info *
> @@ -914,7 +914,7 @@ probe_display(struct drm_i915_private *i915)
>  
>  	if (has_no_display(pdev)) {
>  		drm_dbg_kms(&i915->drm, "Device doesn't have display\n");
> -		return &no_display;
> +		return NULL;
>  	}
>  
>  	for (i = 0; i < ARRAY_SIZE(intel_display_ids); i++) {
> @@ -925,7 +925,7 @@ probe_display(struct drm_i915_private *i915)
>  	drm_dbg(&i915->drm, "No display ID found for device ID %04x; disabling display.\n",
>  		pdev->device);
>  
> -	return &no_display;
> +	return NULL;
>  }
>  
>  void intel_display_device_probe(struct drm_i915_private *i915)
> @@ -943,6 +943,9 @@ void intel_display_device_probe(struct drm_i915_private *i915)
>  	else
>  		info = probe_display(i915);
>  
> +	if (!info)
> +		goto no_display;
> +
>  	DISPLAY_INFO(i915) = info;
>  
>  	memcpy(DISPLAY_RUNTIME_INFO(i915),
> @@ -954,6 +957,11 @@ void intel_display_device_probe(struct drm_i915_private *i915)
>  		DISPLAY_RUNTIME_INFO(i915)->ip.rel = rel;
>  		DISPLAY_RUNTIME_INFO(i915)->ip.step = step;
>  	}
> +
> +	return;
> +
> +no_display:
> +	DISPLAY_INFO(i915) = &no_display;

now I understood why you moved it over and I believe display_runtime_info
is really not needed when no_display, so:

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

>  }
>  
>  void intel_display_device_remove(struct drm_i915_private *i915)
> -- 
> 2.39.2
>