From: Chris Wilson Date: Fri, 17 Jun 2016 17:46:39 +0000 (-0300) Subject: drm/i915: use ORIGIN_CPU for frontbuffer invalidation on WC mmaps X-Git-Tag: v4.9.8~1110^2~42^2~440 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=aeecc9696aa04a82d629e7276134bd54b2afc9e2;p=platform%2Fkernel%2Flinux-rpi3.git drm/i915: use ORIGIN_CPU for frontbuffer invalidation on WC mmaps ... instead of the previous ORIGIN_GTT. This should actually invalidate FBC once something is written on the frontbuffer using WC mmaps. The problem with ORIGIN_GTT is that the automatic hardware tracking is not able to detect the WC writes as it can detect the GTT writes. This should help fix the SKL bug where nothing happens when you type your username/password on lightdm. This patch was originally pasted on an email by Chris and converted to an actual git patch by Paulo. v2 (from Paulo): - Make it a full variable instead of a bit-field (Daniel) - Use WRITE_ONCE (Chris) v3 (from Paulo): - Remove huge comment since now we have WRITE_ONCE (Chris) - Remove uneeded new line (Chris) - Add Chris' Signed-off-by, authorized via IRC Cc: Chris Wilson Reviewed-by: Daniel Vetter Signed-off-by: Chris Wilson Signed-off-by: Paulo Zanoni Link: http://patchwork.freedesktop.org/patch/msgid/1466185599-26401-1-git-send-email-paulo.r.zanoni@intel.com --- diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 0fcf4e4..9e09d91 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2214,6 +2214,7 @@ struct drm_i915_gem_object { unsigned int frontbuffer_bits:INTEL_FRONTBUFFER_BITS; + unsigned int has_wc_mmap; unsigned int pin_display; struct sg_table *pages; diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 604989b..6abd5e5 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1810,6 +1810,13 @@ static struct intel_rps_client *to_rps_client(struct drm_file *file) return &fpriv->rps; } +static enum fb_op_origin +write_origin(struct drm_i915_gem_object *obj, unsigned domain) +{ + return domain == I915_GEM_DOMAIN_GTT && !obj->has_wc_mmap ? + ORIGIN_GTT : ORIGIN_CPU; +} + /** * Called when user space prepares to use an object with the CPU, either * through the mmap ioctl's mapping or a GTT mapping. @@ -1866,9 +1873,7 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data, ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0); if (write_domain != 0) - intel_fb_obj_invalidate(obj, - write_domain == I915_GEM_DOMAIN_GTT ? - ORIGIN_GTT : ORIGIN_CPU); + intel_fb_obj_invalidate(obj, write_origin(obj, write_domain)); unref: drm_gem_object_unreference(&obj->base); @@ -1975,6 +1980,9 @@ i915_gem_mmap_ioctl(struct drm_device *dev, void *data, else addr = -ENOMEM; up_write(&mm->mmap_sem); + + /* This may race, but that's ok, it only gets set */ + WRITE_ONCE(to_intel_bo(obj)->has_wc_mmap, true); } drm_gem_object_unreference_unlocked(obj); if (IS_ERR((void *)addr))