radeon: Call pci_clear_master() instead of open-coding it.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
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>

drivers/gpu/drm/radeon/r100.c

@@ -2186,7 +2186,6 @@ bool r100_gpu_is_lockup(struct radeon_device *rdev, struct radeon_ring *ring)
 void r100_bm_disable(struct radeon_device *rdev)
 {
 	u32 tmp;
-	u16 tmp16;
 
 	/* disable bus mastering */
 	tmp = RREG32(R_000030_BUS_CNTL);
@@ -2197,8 +2196,7 @@ void r100_bm_disable(struct radeon_device *rdev)
 	WREG32(R_000030_BUS_CNTL, (tmp & 0xFFFFFFFF) | 0x00000040);
 	tmp = RREG32(RADEON_BUS_CNTL);
 	mdelay(1);
-	pci_read_config_word(rdev->pdev, 0x4, &tmp16);
-	pci_write_config_word(rdev->pdev, 0x4, tmp16 & 0xFFFB);
+	pci_clear_master(rdev->pdev);
 	mdelay(1);
 }
 

drivers/gpu/drm/radeon/rs600.c

@@ -322,16 +322,6 @@ void rs600_hpd_fini(struct radeon_device *rdev)
 	}
 }
 
-void rs600_bm_disable(struct radeon_device *rdev)
-{
-	u16 tmp;
-
-	/* disable bus mastering */
-	pci_read_config_word(rdev->pdev, 0x4, &tmp);
-	pci_write_config_word(rdev->pdev, 0x4, tmp & 0xFFFB);
-	mdelay(1);
-}
-
 int rs600_asic_reset(struct radeon_device *rdev)
 {
 	struct rv515_mc_save save;
@@ -355,7 +345,8 @@ int rs600_asic_reset(struct radeon_device *rdev)
 	WREG32(RADEON_CP_RB_CNTL, tmp);
 	pci_save_state(rdev->pdev);
 	/* disable bus mastering */
-	rs600_bm_disable(rdev);
+	pci_clear_master(rdev->pdev);
+	mdelay(1);
 	/* reset GA+VAP */
 	WREG32(R_0000F0_RBBM_SOFT_RESET, S_0000F0_SOFT_RESET_VAP(1) |
 					S_0000F0_SOFT_RESET_GA(1));