From 6dfd197283bffc23a2b046a7f065588de7e1fc1e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>
Date: Fri, 5 Jun 2015 13:33:57 -0400
Subject: [PATCH] drm/radeon: fix freeze for laptop with Turks/Thames GPU.
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Laptop with Turks/Thames GPU will freeze if dpm is enabled. It seems
the SMC engine is relying on some state inside the CP engine. CP needs
to chew at least one packet for it to get in good state for dynamic
power management.
This patch simply disabled and re-enable DPM after the ring test which
is enough to avoid the freeze.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/radeon/radeon_device.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index b7ca4c5146212..a7fdfa4f0857b 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -1463,6 +1463,21 @@ int radeon_device_init(struct radeon_device *rdev,
if (r)
DRM_ERROR("ib ring test failed (%d).\n", r);
+ /*
+ * Turks/Thames GPU will freeze whole laptop if DPM is not restarted
+ * after the CP ring have chew one packet at least. Hence here we stop
+ * and restart DPM after the radeon_ib_ring_tests().
+ */
+ if (rdev->pm.dpm_enabled &&
+ (rdev->pm.pm_method == PM_METHOD_DPM) &&
+ (rdev->family == CHIP_TURKS) &&
+ (rdev->flags & RADEON_IS_MOBILITY)) {
+ mutex_lock(&rdev->pm.mutex);
+ radeon_dpm_disable(rdev);
+ radeon_dpm_enable(rdev);
+ mutex_unlock(&rdev->pm.mutex);
+ }
+
if ((radeon_testing & 1)) {
if (rdev->accel_working)
radeon_test_moves(rdev);
--
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