On Wed, May 26, 2021 at 03:30:57PM +0100, Matthew Auld wrote:
> On 26/05/2021 15:14, Tvrtko Ursulin wrote:
> > From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> >
> > Only perform the domain transition under the object lock, and push the
> > required waits to outside the lock.
Do we have actual performance data justifying this? Anything else
justifying this?
If we resurrect patches, I do expect actual review happens here, and
that's not even close the case for this patch here at least. I didn't
bother looking at the others.
-Daniel
> >
> > v2 (Tvrtko):
> > * Rebase.
> >
> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx> # v1
> > Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/gem/i915_gem_clflush.c | 9 +-
> > drivers/gpu/drm/i915/gem/i915_gem_clflush.h | 2 -
> > drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 4 +-
> > drivers/gpu/drm/i915/gem/i915_gem_domain.c | 163 +++++-------------
> > .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 4 +-
> > drivers/gpu/drm/i915/gem/i915_gem_object.h | 12 +-
> > .../gpu/drm/i915/gem/i915_gem_object_types.h | 6 +
> > .../gpu/drm/i915/gem/selftests/huge_pages.c | 8 -
> > .../i915/gem/selftests/i915_gem_coherency.c | 31 +++-
> > .../drm/i915/gem/selftests/i915_gem_phys.c | 8 +-
> > .../drm/i915/gem/selftests/igt_gem_utils.c | 3 +
> > drivers/gpu/drm/i915/i915_gem.c | 4 +-
> > 12 files changed, 89 insertions(+), 165 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
> > index daf9284ef1f5..e4c24558eaa8 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
> > @@ -51,8 +51,6 @@ static struct clflush *clflush_work_create(struct drm_i915_gem_object *obj)
> > {
> > struct clflush *clflush;
> > - GEM_BUG_ON(!obj->cache_dirty);
> > -
> > clflush = kmalloc(sizeof(*clflush), GFP_KERNEL);
> > if (!clflush)
> > return NULL;
> > @@ -101,13 +99,10 @@ bool i915_gem_clflush_object(struct drm_i915_gem_object *obj,
> > trace_i915_gem_object_clflush(obj);
> > - clflush = NULL;
> > - if (!(flags & I915_CLFLUSH_SYNC))
> > - clflush = clflush_work_create(obj);
> > + clflush = clflush_work_create(obj);
> > if (clflush) {
> > i915_sw_fence_await_reservation(&clflush->base.chain,
> > - obj->base.resv, NULL, true,
> > - i915_fence_timeout(to_i915(obj->base.dev)),
> > + obj->base.resv, NULL, true, 0,
> > I915_FENCE_GFP);
> > dma_resv_add_excl_fence(obj->base.resv, &clflush->base.dma);
> > dma_fence_work_commit(&clflush->base);
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.h b/drivers/gpu/drm/i915/gem/i915_gem_clflush.h
> > index e6c382973129..4cd5787d1507 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.h
> > @@ -9,12 +9,10 @@
> > #include <linux/types.h>
> > -struct drm_i915_private;
> > struct drm_i915_gem_object;
> > bool i915_gem_clflush_object(struct drm_i915_gem_object *obj,
> > unsigned int flags);
> > #define I915_CLFLUSH_FORCE BIT(0)
> > -#define I915_CLFLUSH_SYNC BIT(1)
> > #endif /* __I915_GEM_CLFLUSH_H__ */
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
> > index ccede73c6465..0926e0895ee6 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
> > @@ -132,7 +132,7 @@ static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_dire
> > if (!err)
> > err = i915_gem_object_pin_pages(obj);
> > if (!err) {
> > - err = i915_gem_object_set_to_cpu_domain(obj, write);
> > + i915_gem_object_set_to_cpu_domain(obj, write);
> > i915_gem_object_unpin_pages(obj);
> > }
> > if (err == -EDEADLK) {
> > @@ -156,7 +156,7 @@ static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direct
> > if (!err)
> > err = i915_gem_object_pin_pages(obj);
> > if (!err) {
> > - err = i915_gem_object_set_to_gtt_domain(obj, false);
> > + i915_gem_object_set_to_gtt_domain(obj, false);
> > i915_gem_object_unpin_pages(obj);
> > }
> > if (err == -EDEADLK) {
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
> > index 073822100da7..39fda97c49a7 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
> > @@ -49,7 +49,7 @@ flush_write_domain(struct drm_i915_gem_object *obj, unsigned int flush_domains)
> > break;
> > case I915_GEM_DOMAIN_CPU:
> > - i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
> > + i915_gem_clflush_object(obj, 0);
> > break;
> > case I915_GEM_DOMAIN_RENDER:
> > @@ -97,34 +97,13 @@ void i915_gem_object_flush_if_display_locked(struct drm_i915_gem_object *obj)
> > * This function returns when the move is complete, including waiting on
> > * flushes to occur.
> > */
> > -int
> > +void
> > i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write)
> > {
> > - int ret;
> > -
> > assert_object_held(obj);
> > - ret = i915_gem_object_wait(obj,
> > - I915_WAIT_INTERRUPTIBLE |
> > - (write ? I915_WAIT_ALL : 0),
> > - MAX_SCHEDULE_TIMEOUT);
> > - if (ret)
> > - return ret;
> > -
> > if (obj->write_domain == I915_GEM_DOMAIN_WC)
> > - return 0;
> > -
> > - /* Flush and acquire obj->pages so that we are coherent through
> > - * direct access in memory with previous cached writes through
> > - * shmemfs and that our cache domain tracking remains valid.
> > - * For example, if the obj->filp was moved to swap without us
> > - * being notified and releasing the pages, we would mistakenly
> > - * continue to assume that the obj remained out of the CPU cached
> > - * domain.
> > - */
> > - ret = i915_gem_object_pin_pages(obj);
> > - if (ret)
> > - return ret;
> > + return;
> > flush_write_domain(obj, ~I915_GEM_DOMAIN_WC);
> > @@ -145,9 +124,6 @@ i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write)
> > obj->write_domain = I915_GEM_DOMAIN_WC;
> > obj->mm.dirty = true;
> > }
> > -
> > - i915_gem_object_unpin_pages(obj);
> > - return 0;
> > }
> > /**
> > @@ -158,34 +134,13 @@ i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write)
> > * This function returns when the move is complete, including waiting on
> > * flushes to occur.
> > */
> > -int
> > +void
> > i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
> > {
> > - int ret;
> > -
> > assert_object_held(obj);
> > - ret = i915_gem_object_wait(obj,
> > - I915_WAIT_INTERRUPTIBLE |
> > - (write ? I915_WAIT_ALL : 0),
> > - MAX_SCHEDULE_TIMEOUT);
> > - if (ret)
> > - return ret;
> > -
> > if (obj->write_domain == I915_GEM_DOMAIN_GTT)
> > - return 0;
> > -
> > - /* Flush and acquire obj->pages so that we are coherent through
> > - * direct access in memory with previous cached writes through
> > - * shmemfs and that our cache domain tracking remains valid.
> > - * For example, if the obj->filp was moved to swap without us
> > - * being notified and releasing the pages, we would mistakenly
> > - * continue to assume that the obj remained out of the CPU cached
> > - * domain.
> > - */
> > - ret = i915_gem_object_pin_pages(obj);
> > - if (ret)
> > - return ret;
> > + return;
> > flush_write_domain(obj, ~I915_GEM_DOMAIN_GTT);
> > @@ -214,9 +169,6 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
> > i915_vma_set_ggtt_write(vma);
> > spin_unlock(&obj->vma.lock);
> > }
> > -
> > - i915_gem_object_unpin_pages(obj);
> > - return 0;
> > }
> > /**
> > @@ -431,25 +383,23 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
> > * This function returns when the move is complete, including waiting on
> > * flushes to occur.
> > */
> > -int
> > +void
> > i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
> > {
> > - int ret;
> > -
> > assert_object_held(obj);
> > - ret = i915_gem_object_wait(obj,
> > - I915_WAIT_INTERRUPTIBLE |
> > - (write ? I915_WAIT_ALL : 0),
> > - MAX_SCHEDULE_TIMEOUT);
> > - if (ret)
> > - return ret;
> > -
> > flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
> > /* Flush the CPU cache if it's still invalid. */
> > if ((obj->read_domains & I915_GEM_DOMAIN_CPU) == 0) {
> > - i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
> > + /*
> > + * While we track when we write though the CPU cache
> > + * (with obj->cache_dirty), this is only a guide as we do
> > + * not know when the CPU may have speculatively populated
> > + * the cache. We have to invalidate such speculative cachelines
> > + * prior to reading writes by the GPU.
> > + */
> > + i915_gem_clflush_object(obj, 0);
> > obj->read_domains |= I915_GEM_DOMAIN_CPU;
> > }
> > @@ -463,8 +413,6 @@ i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
> > */
> > if (write)
> > __start_cpu_write(obj);
> > -
> > - return 0;
> > }
> > /**
> > @@ -502,32 +450,14 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
> > if (!obj)
> > return -ENOENT;
> > - /*
> > - * Try to flush the object off the GPU without holding the lock.
> > - * We will repeat the flush holding the lock in the normal manner
> > - * to catch cases where we are gazumped.
> > - */
> > - err = i915_gem_object_wait(obj,
> > - I915_WAIT_INTERRUPTIBLE |
> > - I915_WAIT_PRIORITY |
> > - (write_domain ? I915_WAIT_ALL : 0),
> > - MAX_SCHEDULE_TIMEOUT);
> > - if (err)
> > - goto out;
> > -
> > if (i915_gem_object_is_userptr(obj)) {
> > /*
> > * Try to grab userptr pages, iris uses set_domain to check
> > * userptr validity
> > */
> > err = i915_gem_object_userptr_validate(obj);
> > - if (!err)
> > - err = i915_gem_object_wait(obj,
> > - I915_WAIT_INTERRUPTIBLE |
> > - I915_WAIT_PRIORITY |
> > - (write_domain ? I915_WAIT_ALL : 0),
> > - MAX_SCHEDULE_TIMEOUT);
> > - goto out;
> > + if (err)
> > + goto out;
> > }
> > /*
> > @@ -572,11 +502,11 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
> > goto out_unpin;
> > if (read_domains & I915_GEM_DOMAIN_WC)
> > - err = i915_gem_object_set_to_wc_domain(obj, write_domain);
> > + i915_gem_object_set_to_wc_domain(obj, write_domain);
> > else if (read_domains & I915_GEM_DOMAIN_GTT)
> > - err = i915_gem_object_set_to_gtt_domain(obj, write_domain);
> > + i915_gem_object_set_to_gtt_domain(obj, write_domain);
> > else
> > - err = i915_gem_object_set_to_cpu_domain(obj, write_domain);
> > + i915_gem_object_set_to_cpu_domain(obj, write_domain);
> > out_unpin:
> > i915_gem_object_unpin_pages(obj);
> > @@ -584,6 +514,11 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
> > out_unlock:
> > i915_gem_object_unlock(obj);
> > + err = i915_gem_object_wait(obj,
> > + I915_WAIT_INTERRUPTIBLE |
> > + I915_WAIT_PRIORITY |
> > + (write_domain ? I915_WAIT_ALL : 0),
> > + MAX_SCHEDULE_TIMEOUT);
> > if (!err && write_domain)
> > i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
> > @@ -608,26 +543,21 @@ int i915_gem_object_prepare_read(struct drm_i915_gem_object *obj,
> > assert_object_held(obj);
> > - ret = i915_gem_object_wait(obj,
> > - I915_WAIT_INTERRUPTIBLE,
> > - MAX_SCHEDULE_TIMEOUT);
> > - if (ret)
> > - return ret;
> > -
> > ret = i915_gem_object_pin_pages(obj);
> > if (ret)
> > return ret;
> > if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ ||
> > - !static_cpu_has(X86_FEATURE_CLFLUSH)) {
> > - ret = i915_gem_object_set_to_cpu_domain(obj, false);
> > - if (ret)
> > - goto err_unpin;
> > - else
> > - goto out;
> > - }
> > + !static_cpu_has(X86_FEATURE_CLFLUSH))
> > + i915_gem_object_set_to_cpu_domain(obj, false);
> > + else
> > + flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
> > - flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
> > + ret = i915_gem_object_wait(obj,
> > + I915_WAIT_INTERRUPTIBLE,
> > + MAX_SCHEDULE_TIMEOUT);
> > + if (ret)
> > + goto err_unpin;
> > /* If we're not in the cpu read domain, set ourself into the gtt
> > * read domain and manually flush cachelines (if required). This
> > @@ -638,7 +568,6 @@ int i915_gem_object_prepare_read(struct drm_i915_gem_object *obj,
> > !(obj->read_domains & I915_GEM_DOMAIN_CPU))
> > *needs_clflush = CLFLUSH_BEFORE;
> > -out:
> > /* return with the pages pinned */
> > return 0;
> > @@ -658,27 +587,22 @@ int i915_gem_object_prepare_write(struct drm_i915_gem_object *obj,
> > assert_object_held(obj);
> > - ret = i915_gem_object_wait(obj,
> > - I915_WAIT_INTERRUPTIBLE |
> > - I915_WAIT_ALL,
> > - MAX_SCHEDULE_TIMEOUT);
> > - if (ret)
> > - return ret;
> > -
> > ret = i915_gem_object_pin_pages(obj);
> > if (ret)
> > return ret;
> > if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE ||
> > - !static_cpu_has(X86_FEATURE_CLFLUSH)) {
> > - ret = i915_gem_object_set_to_cpu_domain(obj, true);
> > - if (ret)
> > - goto err_unpin;
> > - else
> > - goto out;
> > - }
> > + !static_cpu_has(X86_FEATURE_CLFLUSH))
> > + i915_gem_object_set_to_cpu_domain(obj, true);
> > + else
> > + flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
> > - flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
> > + ret = i915_gem_object_wait(obj,
> > + I915_WAIT_INTERRUPTIBLE |
> > + I915_WAIT_ALL,
> > + MAX_SCHEDULE_TIMEOUT);
> > + if (ret)
> > + goto err_unpin;
> > /* If we're not in the cpu write domain, set ourself into the
> > * gtt write domain and manually flush cachelines (as required).
> > @@ -696,7 +620,6 @@ int i915_gem_object_prepare_write(struct drm_i915_gem_object *obj,
> > *needs_clflush |= CLFLUSH_BEFORE;
> > }
> > -out:
> > i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
> > obj->mm.dirty = true;
> > /* return with the pages pinned */
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > index 297143511f99..40fda9e81a78 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > @@ -1212,9 +1212,7 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj,
> > if (use_cpu_reloc(cache, obj))
> > return NULL;
> > - err = i915_gem_object_set_to_gtt_domain(obj, true);
> > - if (err)
> > - return ERR_PTR(err);
> > + i915_gem_object_set_to_gtt_domain(obj, true);
> > vma = i915_gem_object_ggtt_pin_ww(obj, &eb->ww, NULL, 0, 0,
> > PIN_MAPPABLE |
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > index 2ebd79537aea..8bbc835e70ce 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> > @@ -515,12 +515,12 @@ void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
> > void i915_gem_object_flush_if_display(struct drm_i915_gem_object *obj);
> > void i915_gem_object_flush_if_display_locked(struct drm_i915_gem_object *obj);
> > -int __must_check
> > -i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write);
> > -int __must_check
> > -i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write);
> > -int __must_check
> > -i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write);
> > +void i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj,
> > + bool write);
> > +void i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj,
> > + bool write);
> > +void i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj,
> > + bool write);
> > struct i915_vma * __must_check
> > i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
> > struct i915_gem_ww_ctx *ww,
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > index 0727d0c76aa0..b8f0413bc3b0 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> > @@ -188,6 +188,12 @@ struct drm_i915_gem_object {
> > unsigned int cache_coherent:2;
> > #define I915_BO_CACHE_COHERENT_FOR_READ BIT(0)
> > #define I915_BO_CACHE_COHERENT_FOR_WRITE BIT(1)
> > + /*
> > + * Note cache_dirty is only a guide; we know when we have written
> > + * through the CPU cache, but we do not know when the CPU may have
> > + * speculatively populated the cache. Before a read via the cache
> > + * of GPU written memory, we have to cautiously invalidate the cache.
> > + */
> > unsigned int cache_dirty:1;
> > /**
> > diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> > index 33dd4e2a1010..d85ca79ac433 100644
> > --- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> > +++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> > @@ -972,14 +972,6 @@ static int gpu_write(struct intel_context *ce,
> > u32 dw,
> > u32 val)
> > {
> > - int err;
> > -
> > - i915_gem_object_lock(vma->obj, NULL);
> > - err = i915_gem_object_set_to_gtt_domain(vma->obj, true);
> > - i915_gem_object_unlock(vma->obj);
> > - if (err)
> > - return err;
> > -
> > return igt_gpu_fill_dw(ce, vma, dw * sizeof(u32),
> > vma->size >> PAGE_SHIFT, val);
> > }
> > diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
> > index e937b6629019..77ba6d1ef4e4 100644
> > --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
> > +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
> > @@ -90,8 +90,13 @@ static int gtt_set(struct context *ctx, unsigned long offset, u32 v)
> > int err = 0;
> > i915_gem_object_lock(ctx->obj, NULL);
> > - err = i915_gem_object_set_to_gtt_domain(ctx->obj, true);
> > + i915_gem_object_set_to_gtt_domain(ctx->obj, true);
> > i915_gem_object_unlock(ctx->obj);
> > +
> > + err = i915_gem_object_wait(ctx->obj,
> > + I915_WAIT_ALL |
> > + I915_WAIT_INTERRUPTIBLE,
> > + HZ / 2);
> > if (err)
> > return err;
> > @@ -123,8 +128,12 @@ static int gtt_get(struct context *ctx, unsigned long offset, u32 *v)
> > int err = 0;
> > i915_gem_object_lock(ctx->obj, NULL);
> > - err = i915_gem_object_set_to_gtt_domain(ctx->obj, false);
> > + i915_gem_object_set_to_gtt_domain(ctx->obj, false);
> > i915_gem_object_unlock(ctx->obj);
> > +
> > + err = i915_gem_object_wait(ctx->obj,
> > + I915_WAIT_INTERRUPTIBLE,
> > + HZ / 2);
> > if (err)
> > return err;
> > @@ -155,8 +164,13 @@ static int wc_set(struct context *ctx, unsigned long offset, u32 v)
> > int err;
> > i915_gem_object_lock(ctx->obj, NULL);
> > - err = i915_gem_object_set_to_wc_domain(ctx->obj, true);
> > + i915_gem_object_set_to_wc_domain(ctx->obj, true);
> > i915_gem_object_unlock(ctx->obj);
> > +
> > + err = i915_gem_object_wait(ctx->obj,
> > + I915_WAIT_ALL |
> > + I915_WAIT_INTERRUPTIBLE,
> > + HZ / 2);
> > if (err)
> > return err;
> > @@ -178,8 +192,12 @@ static int wc_get(struct context *ctx, unsigned long offset, u32 *v)
> > int err;
> > i915_gem_object_lock(ctx->obj, NULL);
> > - err = i915_gem_object_set_to_wc_domain(ctx->obj, false);
> > + i915_gem_object_set_to_wc_domain(ctx->obj, false);
> > i915_gem_object_unlock(ctx->obj);
> > +
> > + err = i915_gem_object_wait(ctx->obj,
> > + I915_WAIT_INTERRUPTIBLE,
> > + HZ / 2);
> > if (err)
> > return err;
> > @@ -205,9 +223,7 @@ static int gpu_set(struct context *ctx, unsigned long offset, u32 v)
> > return PTR_ERR(vma);
> > i915_gem_object_lock(ctx->obj, NULL);
> > - err = i915_gem_object_set_to_gtt_domain(ctx->obj, true);
> > - if (err)
> > - goto out_unlock;
> > + i915_gem_object_set_to_gtt_domain(ctx->obj, false);
>
> IIRC Daniel pointed out that this looks odd, since this now becomes
> write=false for some reason. I think keep this as write=true, since it does
> look like that is what gpu_set wants.
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
