Pinning a buffer prevents it from being moved to a different memory
location. For some operations, such as buffer updates, it is not
important where the buffer is located. Setting the pin function's
pl_flag argument to 0 will pin the buffer to whereever it is stored.
Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
---
drivers/gpu/drm/drm_gem_vram_helper.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c
b/drivers/gpu/drm/drm_gem_vram_helper.c
index 42ad80888df7..214f54b8920b 100644
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -224,7 +224,9 @@ EXPORT_SYMBOL(drm_gem_vram_offset);
*
* Pinning a buffer object ensures that it is not evicted from
* a memory region. A pinned buffer object has to be unpinned before
- * it can be pinned to another region.
+ * it can be pinned to another region. If the pl_flag argument is 0,
+ * the buffer is pinned at its current location (video RAM or system
+ * memory).
*
* Returns:
* 0 on success, or
@@ -242,7 +244,9 @@ int drm_gem_vram_pin(struct drm_gem_vram_object *gbo,
unsigned long pl_flag)
if (gbo->pin_count)
goto out;
- drm_gem_vram_placement(gbo, pl_flag);
+ if (pl_flag)
+ drm_gem_vram_placement(gbo, pl_flag);
+
for (i = 0; i < gbo->placement.num_placement; ++i)
gbo->placements[i].flags |= TTM_PL_FLAG_NO_EVICT;
@@ -691,7 +695,7 @@ int drm_gem_vram_driver_gem_prime_pin(struct drm_gem_object
*gem)
{
struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
- return drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
+ return drm_gem_vram_pin(gbo, 0);
}
EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_pin);
@@ -723,7 +727,7 @@ void *drm_gem_vram_driver_gem_prime_vmap(struct
drm_gem_object *gem)
int ret;
void *base;
- ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
+ ret = drm_gem_vram_pin(gbo, 0);
if (ret)
return NULL;
base = drm_gem_vram_kmap(gbo, true, NULL);
--
2.21.0
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