[PATCH] drm/radeon/kms: fix possible mis-detection of sideport on rs690/rs740

[Alex Deucher]

Check ulBootUpMemoryClock on AMD IGPs.

Fix regression noticed by Torsten Kaiser <just.for.lkml at googlemail.com>

Signed-off-by: Alex Deucher <alexdeucher at gmail.com>
Cc: stable at kernel.org
---
 drivers/gpu/drm/radeon/radeon_atombios.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index 5dd86b9..3f89c9b 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -1029,8 +1029,15 @@ bool radeon_atombios_sideport_present(struct radeon_device *rdev)
 				      data_offset);
 		switch (crev) {
 		case 1:
-			if (igp_info->info.ucMemoryType & 0xf0)
-				return true;
+			/* AMD IGPS */
+			if ((rdev->family == CHIP_RS690) ||
+			    (rdev->family == CHIP_RS740)) {
+				if (igp_info->info.ulBootUpMemoryClock)
+					return true;
+			} else {
+				if (igp_info->info.ucMemoryType & 0xf0)
+					return true;
+			}
 			break;
 		case 2:
 			if (igp_info->info_2.ucMemoryType & 0x0f)
-- 
1.7.0.1