On Thu, Jan 11, 2024 at 01:47:02PM +0000, Govindapillai, Vinod wrote:
> Hi Ville
>
> The fix is in the next patch.
>
> This pach changes the 4096 to page size macro as the BUG on is based on that macro explicitly.
I think the whole PAGE_SIZE handling should be in the xe code
since it's an implementation detail of the xe code.
>
> Br
> Vinod
>
> ________________________________
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Sent: Thursday, January 11, 2024 3:44:22 pm
> To: Govindapillai, Vinod <vinod.govindapillai@xxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx <intel-gfx@xxxxxxxxxxxxxxxxxxxxx>; Syrjala, Ville <ville.syrjala@xxxxxxxxx>
> Subject: Re: [PATCH v1 1/2] drm/i915/display: use PAGE_SIZE macro for FBC cfb alloc
>
> On Wed, Jan 10, 2024 at 01:00:08PM +0200, Vinod Govindapillai wrote:
> > FBC compressed frame buffer size need to be PAGE_SIZE aligned
> > and the corresponding the drm_gem functions check the object
> > size alignment using PAGE_SIZE macro. Use the PAGE_SIZE macro
> > in the cfb alloc as well instead of the magic number.
> >
> > Signed-off-by: Vinod Govindapillai <vinod.govindapillai@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/display/intel_fbc.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> > index f17a1afb4929..9b9c8715d664 100644
> > --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> > @@ -764,13 +764,15 @@ static int find_compression_limit(struct intel_fbc *fbc,
> >
> > /* Try to over-allocate to reduce reallocations and fragmentation. */
> > ret = i915_gem_stolen_insert_node_in_range(i915, &fbc->compressed_fb,
> > - size <<= 1, 4096, 0, end);
> > + size <<= 1, PAGE_SIZE, 0,
> > + end);
> > if (ret == 0)
> > return limit;
> >
> > for (; limit <= intel_fbc_max_limit(i915); limit <<= 1) {
> > ret = i915_gem_stolen_insert_node_in_range(i915, &fbc->compressed_fb,
> > - size >>= 1, 4096, 0, end);
> > + size >>= 1, PAGE_SIZE, 0,
> > + end);
>
> PAGE_SIZE is 4k so I can't see this doing anything at all.
>
> The correct fix is probably either:
> - fix the xe gem code to always page align the size
> - page align it in xe's i915_gem_stolen_insert_node_in_range()
>
> > if (ret == 0)
> > return limit;
> > }
> > --
> > 2.34.1
>
> --
> Ville Syrjälä
> Intel
>
--
Ville Syrjälä
Intel
