On Sun, 28 Jun 2015, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > On Sun, Jun 28, 2015 at 09:19:26AM +0100, Chris Wilson wrote: >> The old style of memory interleaving swizzled upto the end of the >> first even bank of memory, and then used the remainder as unswizzled on >> the unpaired bank - i.e. swizzling is not constant for all memory. This >> causes problems when we try to migrate memory and so the kernel prevents >> migration at all when we detect L-shaped inconsistent swizzling. >> However, this issue also extends to userspace who try to manually detile >> into memory as the swizzling for an individual page is unknown (it >> depends on its physical address only known to the kernel), userspace >> cannot correctly swizzle. >> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91105 >> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> >> Cc: stable@xxxxxxxxxxxxxxx >> --- >> drivers/gpu/drm/i915/i915_gem_tiling.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c >> index d16585f788ea..ff96ae9b77bc 100644 >> --- a/drivers/gpu/drm/i915/i915_gem_tiling.c >> +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c >> @@ -447,7 +447,10 @@ i915_gem_get_tiling(struct drm_device *dev, void *data, >> } >> >> /* Hide bit 17 from the user -- see comment in i915_gem_set_tiling */ >> - args->phys_swizzle_mode = args->swizzle_mode; >> + if (dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) >> + args->phys_swizzle_mode = I915_BIT_6_SWIZZLE_UNKNOWN; >> + else >> + args->phys_swizzle_mode = args->swizzle_mode; > > It may be better to store the dev_priv->mm.bit_6_swizzle_[xy] as UNKNOWN > for L-shaped memory. I think that would be more correct. Are you planning on sending an updated patch, or shall I merge this one? BR, Jani. > -Chris > > -- > Chris Wilson, Intel Open Source Technology Centre > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Jani Nikula, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html