drm/radeon: don't use get_engine_clock() on APUs

It doesn't work reliably.  Just report back the currently
selected engine clock.

Partially fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=62493

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/radeon/radeon_pm.c

@@ -843,7 +843,11 @@ static int radeon_debugfs_pm_info(struct seq_file *m, void *data)
 	struct radeon_device *rdev = dev->dev_private;
 
 	seq_printf(m, "default engine clock: %u0 kHz\n", rdev->pm.default_sclk);
-	seq_printf(m, "current engine clock: %u0 kHz\n", radeon_get_engine_clock(rdev));
+	/* radeon_get_engine_clock is not reliable on APUs so just print the current clock */
+	if ((rdev->family >= CHIP_PALM) && (rdev->flags & RADEON_IS_IGP))
+		seq_printf(m, "current engine clock: %u0 kHz\n", rdev->pm.current_sclk);
+	else
+		seq_printf(m, "current engine clock: %u0 kHz\n", radeon_get_engine_clock(rdev));
 	seq_printf(m, "default memory clock: %u0 kHz\n", rdev->pm.default_mclk);
 	if (rdev->asic->pm.get_memory_clock)
 		seq_printf(m, "current memory clock: %u0 kHz\n", radeon_get_memory_clock(rdev));