[PATCH] drm/amd/pm: avoid duplicate powergate/ungate setting

[Evan Quan]

Just bail out if the target IP block is already in the desired
powergate/ungate state. This can avoid some duplicate settings
which sometimes may cause unexpected issues.

Link: https://lore.kernel.org/all/YV81vidWQLWvATMM@zn.tnic/

Change-Id: I66346c69f121df0f5ee20182451313ae4fda2d04
Signed-off-by: Evan Quan <evan.quan at amd.com>
Tested-by: Borislav Petkov <bp at suse.de>
--
v1->v2:
  - typo fix and add link for the issue referred in commit
    message(Paul/Boris)
  - update the data type to uint32_t(Paul)
  - better Macro naming(Lijo)
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  3 +++
 drivers/gpu/drm/amd/include/amd_shared.h   |  3 ++-
 drivers/gpu/drm/amd/pm/amdgpu_dpm.c        | 12 +++++++++++-
 drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h    |  8 ++++++++
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 0bd90ec9e43e..fca592394fa1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3508,6 +3508,9 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 		adev->rmmio_size = pci_resource_len(adev->pdev, 2);
 	}
 
+	for (i = 0; i < AMD_IP_BLOCK_TYPE_NUM; i++)
+		atomic_set(&adev->pm.pwr_state[i], POWER_STATE_UNKNOWN);
+
 	adev->rmmio = ioremap(adev->rmmio_base, adev->rmmio_size);
 	if (adev->rmmio == NULL) {
 		return -ENOMEM;
diff --git a/drivers/gpu/drm/amd/include/amd_shared.h b/drivers/gpu/drm/amd/include/amd_shared.h
index f1a46d16f7ea..4b9e68a79f06 100644
--- a/drivers/gpu/drm/amd/include/amd_shared.h
+++ b/drivers/gpu/drm/amd/include/amd_shared.h
@@ -98,7 +98,8 @@ enum amd_ip_block_type {
 	AMD_IP_BLOCK_TYPE_ACP,
 	AMD_IP_BLOCK_TYPE_VCN,
 	AMD_IP_BLOCK_TYPE_MES,
-	AMD_IP_BLOCK_TYPE_JPEG
+	AMD_IP_BLOCK_TYPE_JPEG,
+	AMD_IP_BLOCK_TYPE_NUM,
 };
 
 enum amd_clockgating_state {
diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
index 03581d5b1836..40fda199a86f 100644
--- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
+++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
@@ -927,6 +927,13 @@ int amdgpu_dpm_set_powergating_by_smu(struct amdgpu_device *adev, uint32_t block
 {
 	int ret = 0;
 	const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
+	enum ip_power_state pwr_state = gate ? POWER_STATE_OFF : POWER_STATE_ON;
+
+	if (atomic_read(&adev->pm.pwr_state[block_type]) == pwr_state) {
+		dev_dbg(adev->dev, "IP block%d already in the target %s state!",
+				block_type, gate ? "gate" : "ungate");
+		return 0;
+	}
 
 	switch (block_type) {
 	case AMD_IP_BLOCK_TYPE_UVD:
@@ -976,9 +983,12 @@ int amdgpu_dpm_set_powergating_by_smu(struct amdgpu_device *adev, uint32_t block
 		}
 		break;
 	default:
-		break;
+		return -EINVAL;
 	}
 
+	if (!ret)
+		atomic_set(&adev->pm.pwr_state[block_type], pwr_state);
+
 	return ret;
 }
 
diff --git a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
index 98f1b3d8c1d5..16e3f72d31b9 100644
--- a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
+++ b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
@@ -417,6 +417,12 @@ struct amdgpu_dpm {
 	enum amd_dpm_forced_level forced_level;
 };
 
+enum ip_power_state {
+	POWER_STATE_UNKNOWN,
+	POWER_STATE_ON,
+	POWER_STATE_OFF,
+};
+
 struct amdgpu_pm {
 	struct mutex		mutex;
 	u32                     current_sclk;
@@ -452,6 +458,8 @@ struct amdgpu_pm {
 	struct i2c_adapter smu_i2c;
 	struct mutex		smu_i2c_mutex;
 	struct list_head	pm_attr_list;
+
+	atomic_t		pwr_state[AMD_IP_BLOCK_TYPE_NUM];
 };
 
 #define R600_SSTU_DFLT                               0
-- 
2.29.0