| Message ID | 20230309164905.828-1-nirmoy.das@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/mtl: Disable stolen memory backed FB for A0 | expand |
Hi Nirmoy, On Thu, Mar 09, 2023 at 05:49:05PM +0100, Nirmoy Das wrote: > Stolen memory is not usable for MTL A0 stepping beyond > certain access size and we have no control over userspace > access size of /dev/fb which can be backed by stolen memory. > So disable stolen memory backed fb by setting i915->dsm.usable_size > to zero. > > Cc: Matthew Auld <matthew.auld@intel.com> > Cc: Andi Shyti <andi.shyti@linux.intel.com> > Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> > Cc: Lucas De Marchi <lucas.demarchi@intel.com> > Can you please remove this blank line from the tag space? > Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> > --- > drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > index d8e06e783e30..56ccfcbdbce1 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > @@ -535,6 +535,16 @@ static int i915_gem_init_stolen(struct intel_memory_region *mem) > /* Basic memrange allocator for stolen space. */ > drm_mm_init(&i915->mm.stolen, 0, i915->dsm.usable_size); > > + /* > + * Access to stolen lmem beyond certain size for MTL A0 stepping > + * would crash the machine. Disable stolen lmem for userspace access > + * by setting usable_size to zero. > + * hsdes: 22016134735 Please, remove this reference, as well. With the above: Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> Thanks, Andi > + */ > + if (IS_MTL_GRAPHICS_STEP(i915, M, STEP_A0, STEP_B0) || > + IS_MTL_GRAPHICS_STEP(i915, P, STEP_A0, STEP_B0)) > + i915->dsm.usable_size = 0; > + > return 0; > } > > -- > 2.39.0
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c index d8e06e783e30..56ccfcbdbce1 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c @@ -535,6 +535,16 @@ static int i915_gem_init_stolen(struct intel_memory_region *mem) /* Basic memrange allocator for stolen space. */ drm_mm_init(&i915->mm.stolen, 0, i915->dsm.usable_size); + /* + * Access to stolen lmem beyond certain size for MTL A0 stepping + * would crash the machine. Disable stolen lmem for userspace access + * by setting usable_size to zero. + * hsdes: 22016134735 + */ + if (IS_MTL_GRAPHICS_STEP(i915, M, STEP_A0, STEP_B0) || + IS_MTL_GRAPHICS_STEP(i915, P, STEP_A0, STEP_B0)) + i915->dsm.usable_size = 0; + return 0; }
Stolen memory is not usable for MTL A0 stepping beyond certain access size and we have no control over userspace access size of /dev/fb which can be backed by stolen memory. So disable stolen memory backed fb by setting i915->dsm.usable_size to zero. Cc: Matthew Auld <matthew.auld@intel.com> Cc: Andi Shyti <andi.shyti@linux.intel.com> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Nirmoy Das <nirmoy.das@intel.com> --- drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 10 ++++++++++ 1 file changed, 10 insertions(+)