[ 07/73] drm/radeon/kms: fix MSI re-arm on rv370+

[Greg KH]

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alex Deucher <alexander.deucher@xxxxxxx>

commit b7f5b7dec3d539a84734f2bcb7e53fbb1532a40b upstream.

MSI_REARM_EN register is a write only trigger register.
There is no need RMW when re-arming.

May fix:
https://bugs.freedesktop.org/show_bug.cgi?id=41668

Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/radeon/r100.c  |    4 +---
 drivers/gpu/drm/radeon/rs600.c |    4 +---
 2 files changed, 2 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -681,9 +681,7 @@ int r100_irq_process(struct radeon_devic
 			WREG32(RADEON_AIC_CNTL, msi_rearm | RS400_MSI_REARM);
 			break;
 		default:
-			msi_rearm = RREG32(RADEON_MSI_REARM_EN) & ~RV370_MSI_REARM_EN;
-			WREG32(RADEON_MSI_REARM_EN, msi_rearm);
-			WREG32(RADEON_MSI_REARM_EN, msi_rearm | RV370_MSI_REARM_EN);
+			WREG32(RADEON_MSI_REARM_EN, RV370_MSI_REARM_EN);
 			break;
 		}
 	}
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -698,9 +698,7 @@ int rs600_irq_process(struct radeon_devi
 			WREG32(RADEON_BUS_CNTL, msi_rearm | RS600_MSI_REARM);
 			break;
 		default:
-			msi_rearm = RREG32(RADEON_MSI_REARM_EN) & ~RV370_MSI_REARM_EN;
-			WREG32(RADEON_MSI_REARM_EN, msi_rearm);
-			WREG32(RADEON_MSI_REARM_EN, msi_rearm | RV370_MSI_REARM_EN);
+			WREG32(RADEON_MSI_REARM_EN, RV370_MSI_REARM_EN);
 			break;
 		}
 	}


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