From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 3 Mar 2015 01:43:53 +0000 (-0500)
Subject: drm/radeon: do a posting read in si_set_irq
X-Git-Tag: v3.4.108~106
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=63a445d34e5edc8e59d9888e9837c34b02d51b91;p=thirdparty%2Fkernel%2Fstable.git

drm/radeon: do a posting read in si_set_irq

commit 0586915ec10d0ae60de5cd3381ad25a704760402 upstream.

To make sure the writes go through the pci bridge.

bug:
https://bugzilla.kernel.org/show_bug.cgi?id=90741

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---

diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index e710073923e97..068b21f0d7df8 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -4126,6 +4126,9 @@ int si_init(struct radeon_device *rdev)
 		return -EINVAL;
 	}
 
+	/* posting read */
+	RREG32(SRBM_STATUS);
+
 	return 0;
 }