[Intel-gfx] [PATCH 2/2] drm/i915: restore stolen memory behaviour for DG2

[Lucas De Marchi]

On Wed, Oct 05, 2022 at 04:31:48PM +0100, Matthew Auld wrote:
>Restore the previous behaviour here where we compare the
>pci_resource_len() with the actual lmem_size, and not the dsm size,
>since dsm here is just some subset snipped off the end of the lmem.
>Otherwise we will incorrectly report an io_size > 0 on small-bar
>systems.
>
>It doesn't looks like MTL is expecting small-bar with its stolen memory,
>based on:
>
>  GEM_BUG_ON(pci_resource_len(pdev, GEN12_LMEM_BAR) != SZ_256M)
>  GEM_BUG_ON((dsm_size + SZ_8M) > lmem_size)
>
>So just move the HAS_BAR2_SMEM_STOLEN() check first, which then ignores
>the small bar part, and we can go back to checking lmem_size against the
>BAR size.
>
>Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7007
>Fixes: dbb2ffbfd708 ("drm/i915/mtl: enable local stolen memory")
>Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>Cc: Aravind Iddamsetty <aravind.iddamsetty at intel.com>
>Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>Cc: Matt Roper <matthew.d.roper at intel.com>


Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

Lucas De Marchi