[Intel-xe] [PATCH 3/4] drm/xe/display: Consider has_display to enable it

[Souza, Jose]

On Wed, 2023-05-10 at 12:54 -0700, Lucas De Marchi wrote:
> Stop the dance of enabling the display-related driver_features to later
> disable them on display info init if the platform doesn't have display
> IP. Besides being needless work, it wasn't covering the ATS-M case that
> is the same platform as DG2, but without display.

Xe should set pipe_mask = 0 and call i915 functions that will handle no display cases.
Also intel_device_info_runtime_init() needs to be called earlier, as pipes could be fused off and there is a case for discrete platforms with display
>= 14 that can have display fused off too.

> 
> Since now the display is created after the complete device info is
> populated, the new has_display flag can be consider to enable it.
> 
> References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/265
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.c  | 1 -
>  drivers/gpu/drm/xe/xe_display.c | 6 ++++--
>  drivers/gpu/drm/xe/xe_pci.c     | 6 +++++-
>  3 files changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 32cc83c43b2a..1daacc533083 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -192,7 +192,6 @@ struct xe_device *xe_device_create(struct pci_dev *pdev,
>  	xe->info.devid = pdev->device;
>  	xe->info.revid = pdev->revision;
>  	xe->info.enable_guc = enable_guc;
> -	xe->info.enable_display = enable_display;
>  
>  	spin_lock_init(&xe->irq.lock);
>  
> diff --git a/drivers/gpu/drm/xe/xe_display.c b/drivers/gpu/drm/xe/xe_display.c
> index 77a158ecf4cb..43c5af1ff80e 100644
> --- a/drivers/gpu/drm/xe/xe_display.c
> +++ b/drivers/gpu/drm/xe/xe_display.c
> @@ -487,8 +487,10 @@ __diag_ignore_all("-Woverride-init", "Allow field overrides in table");
>  
>  void xe_display_info_init(struct xe_device *xe)
>  {
> -	if (!xe->info.enable_display)
> +	if (!xe->info.enable_display) {
> +		unset_driver_hooks(xe);
>  		return;
> +	}
>  
>  	switch (xe->info.platform) {
>  	case XE_TIGERLAKE:
> @@ -535,7 +537,7 @@ void xe_display_info_init(struct xe_device *xe)
>  		xe->info.display = (struct xe_device_display_info) { XE_LPDP };
>  		break;
>  	default:
> -		drm_dbg(&xe->drm, "No display IP, skipping\n");
> +		drm_warn(&xe->drm, "Unknown display IP\n");
>  		xe->info.enable_display = false;
>  		unset_driver_hooks(xe);
>  		return;
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index 7dfbc4fa138a..3fa3e8706d98 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -529,6 +529,9 @@ static int xe_info_init(struct xe_device *xe,
>  	xe->info.has_range_tlb_invalidation = graphics_desc->has_range_tlb_invalidation;
>  	xe->info.has_link_copy_engine = graphics_desc->has_link_copy_engine;
>  
> +	xe->info.enable_display = IS_ENABLED(CONFIG_DRM_DISPLAY) && \
> +				  enable_display && \
> +				  desc->has_display;
>  	/*
>  	 * All platforms have at least one primary GT.  Any platform with media
>  	 * version 13 or higher has an additional dedicated media GT.  And
> @@ -629,7 +632,7 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  
>  	xe_display_info_init(xe);
>  
> -	drm_dbg(&xe->drm, "%s %s %04x:%04x dgfx:%d gfx:%s (%d.%02d) media:%s (%d.%02d) dma_m_s:%d tc:%d",
> +	drm_dbg(&xe->drm, "%s %s %04x:%04x dgfx:%d gfx:%s (%d.%02d) media:%s (%d.%02d) display:%s dma_m_s:%d tc:%d",
>  		desc->platform_name,
>  		subplatform_desc ? subplatform_desc->name : "",
>  		xe->info.devid, xe->info.revid,
> @@ -640,6 +643,7 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  		xe->info.media_name,
>  		xe->info.media_verx100 / 100,
>  		xe->info.media_verx100 % 100,
> +		str_yes_no(xe->info.enable_display),
>  		xe->info.dma_mask_size, xe->info.tile_count);
>  
>  	drm_dbg(&xe->drm, "Stepping = (G:%s, M:%s, D:%s, B:%s)\n",