drm/radeon/kms/r7xx: add workaround for hw issue with HDP flush
Use of HDP_*_COHERENCY_FLUSH_CNTL can cause a hang in certain
situations. Add workaround.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index e1e59e1..28e39bc 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -884,7 +884,17 @@
u32 tmp;
/* flush hdp cache so updates hit vram */
- WREG32(R_005480_HDP_MEM_COHERENCY_FLUSH_CNTL, 0x1);
+ if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740)) {
+ void __iomem *ptr = (void *)rdev->gart.table.vram.ptr;
+ u32 tmp;
+
+ /* r7xx hw bug. write to HDP_DEBUG1 followed by fb read
+ * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL
+ */
+ WREG32(HDP_DEBUG1, 0);
+ tmp = readl((void __iomem *)ptr);
+ } else
+ WREG32(R_005480_HDP_MEM_COHERENCY_FLUSH_CNTL, 0x1);
WREG32(VM_CONTEXT0_INVALIDATION_LOW_ADDR, rdev->mc.gtt_start >> 12);
WREG32(VM_CONTEXT0_INVALIDATION_HIGH_ADDR, (rdev->mc.gtt_end - 1) >> 12);
@@ -3527,5 +3537,15 @@
*/
void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo)
{
- WREG32(R_005480_HDP_MEM_COHERENCY_FLUSH_CNTL, 0x1);
+ /* r7xx hw bug. write to HDP_DEBUG1 followed by fb read
+ * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL
+ */
+ if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740)) {
+ void __iomem *ptr = (void *)rdev->gart.table.vram.ptr;
+ u32 tmp;
+
+ WREG32(HDP_DEBUG1, 0);
+ tmp = readl((void __iomem *)ptr);
+ } else
+ WREG32(R_005480_HDP_MEM_COHERENCY_FLUSH_CNTL, 0x1);
}