drm/radeon: Don't read from CP ring write pointer registers.

commit 87463ff83bcda210d8f0ae440bd64d1548f852e7 upstream.

Apparently this doesn't always work reliably, e.g. at resume time.

Just initialize to 0, so the ring is considered empty.

Tested with hibernation on Sumo and Cayman cards.

Should fix https://bugs.launchpad.net/ubuntu/+source/linux/+bug/820746/ .

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 12 insertions, 14 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 2b2f06c12ba2..ac7f700b5c47 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -1404,7 +1404,8 @@ int evergreen_cp_resume(struct radeon_device *rdev)
 	/* Initialize the ring buffer's read and write pointers */
 	WREG32(CP_RB_CNTL, tmp | RB_RPTR_WR_ENA);
 	WREG32(CP_RB_RPTR_WR, 0);
-	WREG32(CP_RB_WPTR, 0);
+	rdev->cp.wptr = 0;
+	WREG32(CP_RB_WPTR, rdev->cp.wptr);
 
 	/* set the wb address wether it's enabled or not */
 	WREG32(CP_RB_RPTR_ADDR,
@@ -1429,7 +1430,6 @@ int evergreen_cp_resume(struct radeon_device *rdev)
 	WREG32(CP_DEBUG, (1 << 27) | (1 << 28));
 
 	rdev->cp.rptr = RREG32(CP_RB_RPTR);
-	rdev->cp.wptr = RREG32(CP_RB_WPTR);
 
 	evergreen_cp_start(rdev);
 	rdev->cp.ready = true;
diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 8261e3ee96fb..0b132a3b1df9 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -1186,7 +1186,8 @@ int cayman_cp_resume(struct radeon_device *rdev)
 
 	/* Initialize the ring buffer's read and write pointers */
 	WREG32(CP_RB0_CNTL, tmp | RB_RPTR_WR_ENA);
-	WREG32(CP_RB0_WPTR, 0);
+	rdev->cp.wptr = 0;
+	WREG32(CP_RB0_WPTR, rdev->cp.wptr);
 
 	/* set the wb address wether it's enabled or not */
 	WREG32(CP_RB0_RPTR_ADDR, (rdev->wb.gpu_addr + RADEON_WB_CP_RPTR_OFFSET) & 0xFFFFFFFC);
@@ -1206,7 +1207,6 @@ int cayman_cp_resume(struct radeon_device *rdev)
 	WREG32(CP_RB0_BASE, rdev->cp.gpu_addr >> 8);
 
 	rdev->cp.rptr = RREG32(CP_RB0_RPTR);
-	rdev->cp.wptr = RREG32(CP_RB0_WPTR);
 
 	/* ring1  - compute only */
 	/* Set ring buffer size */
@@ -1219,7 +1219,8 @@ int cayman_cp_resume(struct radeon_device *rdev)
 
 	/* Initialize the ring buffer's read and write pointers */
 	WREG32(CP_RB1_CNTL, tmp | RB_RPTR_WR_ENA);
-	WREG32(CP_RB1_WPTR, 0);
+	rdev->cp1.wptr = 0;
+	WREG32(CP_RB1_WPTR, rdev->cp1.wptr);
 
 	/* set the wb address wether it's enabled or not */
 	WREG32(CP_RB1_RPTR_ADDR, (rdev->wb.gpu_addr + RADEON_WB_CP1_RPTR_OFFSET) & 0xFFFFFFFC);
@@ -1231,7 +1232,6 @@ int cayman_cp_resume(struct radeon_device *rdev)
 	WREG32(CP_RB1_BASE, rdev->cp1.gpu_addr >> 8);
 
 	rdev->cp1.rptr = RREG32(CP_RB1_RPTR);
-	rdev->cp1.wptr = RREG32(CP_RB1_WPTR);
 
 	/* ring2 - compute only */
 	/* Set ring buffer size */
@@ -1244,7 +1244,8 @@ int cayman_cp_resume(struct radeon_device *rdev)
 
 	/* Initialize the ring buffer's read and write pointers */
 	WREG32(CP_RB2_CNTL, tmp | RB_RPTR_WR_ENA);
-	WREG32(CP_RB2_WPTR, 0);
+	rdev->cp2.wptr = 0;
+	WREG32(CP_RB2_WPTR, rdev->cp2.wptr);
 
 	/* set the wb address wether it's enabled or not */
 	WREG32(CP_RB2_RPTR_ADDR, (rdev->wb.gpu_addr + RADEON_WB_CP2_RPTR_OFFSET) & 0xFFFFFFFC);
@@ -1256,7 +1257,6 @@ int cayman_cp_resume(struct radeon_device *rdev)
 	WREG32(CP_RB2_BASE, rdev->cp2.gpu_addr >> 8);
 
 	rdev->cp2.rptr = RREG32(CP_RB2_RPTR);
-	rdev->cp2.wptr = RREG32(CP_RB2_WPTR);
 
 	/* start the rings */
 	cayman_cp_start(rdev);
diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index f2204cb1ccdf..11e44a3479e3 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -990,7 +990,8 @@ int r100_cp_init(struct radeon_device *rdev, unsigned ring_size)
 	/* Force read & write ptr to 0 */
 	WREG32(RADEON_CP_RB_CNTL, tmp | RADEON_RB_RPTR_WR_ENA | RADEON_RB_NO_UPDATE);
 	WREG32(RADEON_CP_RB_RPTR_WR, 0);
-	WREG32(RADEON_CP_RB_WPTR, 0);
+	rdev->cp.wptr = 0;
+	WREG32(RADEON_CP_RB_WPTR, rdev->cp.wptr);
 
 	/* set the wb address whether it's enabled or not */
 	WREG32(R_00070C_CP_RB_RPTR_ADDR,
@@ -1007,9 +1008,6 @@ int r100_cp_init(struct radeon_device *rdev, unsigned ring_size)
 	WREG32(RADEON_CP_RB_CNTL, tmp);
 	udelay(10);
 	rdev->cp.rptr = RREG32(RADEON_CP_RB_RPTR);
-	rdev->cp.wptr = RREG32(RADEON_CP_RB_WPTR);
-	/* protect against crazy HW on resume */
-	rdev->cp.wptr &= rdev->cp.ptr_mask;
 	/* Set cp mode to bus mastering & enable cp*/
 	WREG32(RADEON_CP_CSQ_MODE,
 	       REG_SET(RADEON_INDIRECT2_START, indirect2_start) |
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index bc54b26cb32f..8ca098d4a783 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -2208,7 +2208,8 @@ int r600_cp_resume(struct radeon_device *rdev)
 	/* Initialize the ring buffer's read and write pointers */
 	WREG32(CP_RB_CNTL, tmp | RB_RPTR_WR_ENA);
 	WREG32(CP_RB_RPTR_WR, 0);
-	WREG32(CP_RB_WPTR, 0);
+	rdev->cp.wptr = 0;
+	WREG32(CP_RB_WPTR, rdev->cp.wptr);
 
 	/* set the wb address whether it's enabled or not */
 	WREG32(CP_RB_RPTR_ADDR,
@@ -2233,7 +2234,6 @@ int r600_cp_resume(struct radeon_device *rdev)
 	WREG32(CP_DEBUG, (1 << 27) | (1 << 28));
 
 	rdev->cp.rptr = RREG32(CP_RB_RPTR);
-	rdev->cp.wptr = RREG32(CP_RB_WPTR);
 
 	r600_cp_start(rdev);
 	rdev->cp.ready = true;