On Wed, 2015-08-05 at 14:48 -0700, Kamal Mostafa wrote: > 3.19.8-ckt5 -stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > commit 19ee835cdb0b5a8eb11a68f25a51b8039d564488 upstream. > > The old style of memory interleaving swizzled upto the end of the > first even bank of memory, I notice now that this commit was been reverted and replaced. I'll drop this from 3.19-stable and use the replacement 5eb3e5a instead. 5eb3e5a drm/i915: Declare the swizzling unknown for L-shaped configurations d82c0ba Revert "drm/i915: Declare the swizzling unknown for L-shaped configurations" 19ee835 drm/i915: Declare the swizzling unknown for L-shaped configurations -Kamal > 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 objects. > > v2: Mark the global swizzling as unknown rather than adjust the value > reported to userspace. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91105 > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_gem_tiling.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c > index ffe9072..8ce8c5e 100644 > --- a/drivers/gpu/drm/i915/i915_gem_tiling.c > +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c > @@ -183,8 +183,18 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev) > if (IS_GEN4(dev)) { > uint32_t ddc2 = I915_READ(DCC2); > > - if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE)) > + if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE)) { > + /* Since the swizzling may vary within an > + * object, we have no idea what the swizzling > + * is for any page in particular. Thus we > + * cannot migrate tiled pages using the GPU, > + * nor can we tell userspace what the exact > + * swizzling is for any object. > + */ > dev_priv->quirks |= QUIRK_PIN_SWIZZLED_PAGES; > + swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN; > + swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN; > + } > } > > if (dcc == 0xffffffff) { -- 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