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

Check ulBootUpMemoryClock on AMD IGPs.

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

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

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 99bd8a9c56b..125155af888 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)