drm/radeon/kms: avoid oops on mac r4xx cards

They don't have an atombios so don't attempt to use it for
eng/mem clocks.

Reported by spoonb on #radeon
fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=28671

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

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_asic.c b/drivers/gpu/drm/radeon/radeon_asic.c
index 87f7e2cc52d4..646f96f97c77 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.c
+++ b/drivers/gpu/drm/radeon/radeon_asic.c
@@ -780,6 +780,13 @@ int radeon_asic_init(struct radeon_device *rdev)
         case CHIP_R423:
         case CHIP_RV410:
                 rdev->asic = &r420_asic;
+                /* handle macs */
+                if (rdev->bios == NULL) {
+                        rdev->asic->get_engine_clock = &radeon_legacy_get_engine_clock;
+                        rdev->asic->set_engine_clock = &radeon_legacy_set_engine_clock;
+                        rdev->asic->get_memory_clock = &radeon_legacy_get_memory_clock;
+                        rdev->asic->set_memory_clock = NULL;
+                }
                 break;
         case CHIP_RS400:
         case CHIP_RS480: