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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 03add5d5542e49fb2a0e84fcf27548fd5c2a9ee7..87dbbb65769b3a40cbee93a8c4294337ebc3583b 100644 (file)
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -5778,5 +5778,8 @@ int si_set_uvd_clocks(struct radeon_device *rdev, u32 vclk, u32 dclk)
 
        mdelay(100);
 
+       /* posting read */
+       RREG32(SRBM_STATUS);
+
        return 0;
 }