> -----Original Message-----
> From: Intel-gfx <intel-gfx-boun...@lists.freedesktop.org> On Behalf Of Ville
> Syrjala
> Sent: Tuesday, January 16, 2024 1:26 PM
> To: intel-gfx@lists.freedesktop.org
> Subject: [PATCH v3 08/16] drm/i915: Fix region start during initial plane
> readout
>
> From: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> On MTL the stolen region starts at offset 8MiB from the start of LMEMBAR. The
> dma addresses are thus also offset by 8MiB. However the mm_node/etc. is zero
> based, and i915_pages_create_for_stolen() will add the appropriate
> region.start
> into the sg dma address. So when we do the readout we need to convert the dma
> address read from the PTE to be zero based as well.
>
> Note that currently we don't take this path on MTL, but we should and thus
> this
> needs to be fixed. For lmem this works correctly already as the lmem
> region.start==0.
>
> While at it let's also make sure the address points to somewhere within the
> memory region. We don't need to check the size as
> i915_gem_object_create_region_at() should later fail if the object size
> exceeds
> the region size.
Looks Good to me.
Reviewed-by: Uma Shankar <uma.shan...@intel.com>
> Cc: Paz Zcharya <p...@chromium.org>
> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_plane_initial.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_plane_initial.c
> b/drivers/gpu/drm/i915/display/intel_plane_initial.c
> index ffc92b18fcf5..db594ccf0323 100644
> --- a/drivers/gpu/drm/i915/display/intel_plane_initial.c
> +++ b/drivers/gpu/drm/i915/display/intel_plane_initial.c
> @@ -79,16 +79,18 @@ initial_plane_vma(struct drm_i915_private *i915,
> * We don't currently expect this to ever be placed in the
> * stolen portion.
> */
> - if (phys_base >= resource_size(&mem->region)) {
> + if (phys_base < mem->region.start || phys_base > mem-
> >region.end) {
> drm_err(&i915->drm,
> - "Initial plane programming using invalid range,
> phys_base=%pa\n",
> - &phys_base);
> + "Initial plane programming using invalid range,
> phys_base=%pa (%s [%pa-%pa])\n",
> + &phys_base, mem->region.name, &mem-
> >region.start,
> +&mem->region.end);
> return NULL;
> }
>
> drm_dbg(&i915->drm,
> "Using phys_base=%pa, based on initial plane
> programming\n",
> &phys_base);
> +
> + phys_base -= mem->region.start;
> } else {
> phys_base = base;
> mem = i915->mm.stolen_region;
> --
> 2.41.0
