drm/radeon: Workaround radeon driver bug for Loongson

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5OHOB

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

Radeon driver can not handle the interrupt is faster than DMA data, so
irq handler must update an old ih.rptr value in IH_RB_RPTR register to
enable interrupt again when interrupt is faster than DMA data.

Change-Id: If15325e6c22c6e01e0fdf78588f0b4f2fd4ef569
Signed-off-by: NHuacai Chen <chenhuacai@loongson.cn>
Signed-off-by: NZhijie Zhang <zhangzhijie@loongson.cn>

drivers/gpu/drm/radeon/cik.c

@@ -8108,6 +8108,7 @@ int cik_irq_process(struct radeon_device *rdev)
 	if (queue_thermal)
 		schedule_work(&rdev->pm.dpm.thermal.work);
 	rdev->ih.rptr = rptr;
+	WREG32(IH_RB_RPTR, rptr);
 	atomic_set(&rdev->ih.lock, 0);
 
 	/* make sure wptr hasn't changed while processing */

drivers/gpu/drm/radeon/evergreen.c

@@ -4919,6 +4919,7 @@ int evergreen_irq_process(struct radeon_device *rdev)
 	if (queue_thermal && rdev->pm.dpm_enabled)
 		schedule_work(&rdev->pm.dpm.thermal.work);
 	rdev->ih.rptr = rptr;
+	WREG32(IH_RB_RPTR, rptr);
 	atomic_set(&rdev->ih.lock, 0);
 
 	/* make sure wptr hasn't changed while processing */

drivers/gpu/drm/radeon/r600.c

@@ -4331,6 +4331,7 @@ int r600_irq_process(struct radeon_device *rdev)
 	if (queue_thermal && rdev->pm.dpm_enabled)
 		schedule_work(&rdev->pm.dpm.thermal.work);
 	rdev->ih.rptr = rptr;
+	WREG32(IH_RB_RPTR, rptr);
 	atomic_set(&rdev->ih.lock, 0);
 
 	/* make sure wptr hasn't changed while processing */

drivers/gpu/drm/radeon/si.c

@@ -6443,6 +6443,7 @@ int si_irq_process(struct radeon_device *rdev)
 	if (queue_thermal && rdev->pm.dpm_enabled)
 		schedule_work(&rdev->pm.dpm.thermal.work);
 	rdev->ih.rptr = rptr;
+	WREG32(IH_RB_RPTR, rptr);
 	atomic_set(&rdev->ih.lock, 0);
 
 	/* make sure wptr hasn't changed while processing */