drm/radeon/kms: Don't RMW CP_RB_CNTL

Immediate readback seems faulty on some chips. I suspect it takes a while to get through the fifo to the actual register backbone. There's no need to read it back, so, just write the driver's copy of the register's value directly. Should fix bug 24535 and possibly 24218 Signed-off-by: Alex Deucher <[email protected]> Signed-off-by: Dave Airlie <[email protected]>
kyagi · Nov 3, 2009 · d6f2893 · d6f2893
1 parent df67bed
commit d6f2893
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Showing 2 changed files with 9 additions and 11 deletions.
diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
@@ -578,19 +578,19 @@ int r100_cp_init(struct radeon_device *rdev, unsigned ring_size)
 	indirect1_start = 16;
 	/* cp setup */
 	WREG32(0x718, pre_write_timer | (pre_write_limit << 28));
-	WREG32(RADEON_CP_RB_CNTL,
-#ifdef __BIG_ENDIAN
-	       RADEON_BUF_SWAP_32BIT |
-#endif
-	       REG_SET(RADEON_RB_BUFSZ, rb_bufsz) |
+	tmp = (REG_SET(RADEON_RB_BUFSZ, rb_bufsz) |
 	       REG_SET(RADEON_RB_BLKSZ, rb_blksz) |
 	       REG_SET(RADEON_MAX_FETCH, max_fetch) |
 	       RADEON_RB_NO_UPDATE);
+#ifdef __BIG_ENDIAN
+	tmp |= RADEON_BUF_SWAP_32BIT;
+#endif
+	WREG32(RADEON_CP_RB_CNTL, tmp);
+
 	/* Set ring address */
 	DRM_INFO("radeon: ring at 0x%016lX\n", (unsigned long)rdev->cp.gpu_addr);
 	WREG32(RADEON_CP_RB_BASE, rdev->cp.gpu_addr);
 	/* Force read & write ptr to 0 */
-	tmp = RREG32(RADEON_CP_RB_CNTL);
 	WREG32(RADEON_CP_RB_CNTL, tmp | RADEON_RB_RPTR_WR_ENA);
 	WREG32(RADEON_CP_RB_RPTR_WR, 0);
 	WREG32(RADEON_CP_RB_WPTR, 0);

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
@@ -1272,19 +1272,17 @@ int r600_cp_resume(struct radeon_device *rdev)
 
 	/* Set ring buffer size */
 	rb_bufsz = drm_order(rdev->cp.ring_size / 8);
+	tmp = RB_NO_UPDATE | (drm_order(RADEON_GPU_PAGE_SIZE/8) << 8) | rb_bufsz;
 #ifdef __BIG_ENDIAN
-	WREG32(CP_RB_CNTL, BUF_SWAP_32BIT | RB_NO_UPDATE |
-		(drm_order(RADEON_GPU_PAGE_SIZE/8) << 8) | rb_bufsz);
-#else
-	WREG32(CP_RB_CNTL, RB_NO_UPDATE | (drm_order(RADEON_GPU_PAGE_SIZE/8) << 8) | rb_bufsz);
+	tmp |= BUF_SWAP_32BIT;
 #endif
+	WREG32(CP_RB_CNTL, tmp);
 	WREG32(CP_SEM_WAIT_TIMER, 0x4);
 
 	/* Set the write pointer delay */
 	WREG32(CP_RB_WPTR_DELAY, 0);
 
 	/* Initialize the ring buffer's read and write pointers */
-	tmp = RREG32(CP_RB_CNTL);
 	WREG32(CP_RB_CNTL, tmp | RB_RPTR_WR_ENA);
 	WREG32(CP_RB_RPTR_WR, 0);
 	WREG32(CP_RB_WPTR, 0);