[PATCH 1/4] drm/amd/pm: drop unnecessary feature->mutex lock protections(V2)

[Quan, Evan]

[AMD Official Use Only - Internal Distribution Only]

Ping..

-----Original Message-----
From: Quan, Evan <Evan.Quan at amd.com>
Sent: Tuesday, August 25, 2020 3:49 PM
To: amd-gfx at lists.freedesktop.org
Cc: Deucher, Alexander <Alexander.Deucher at amd.com>; Quan, Evan <Evan.Quan at amd.com>
Subject: [PATCH 1/4] drm/amd/pm: drop unnecessary feature->mutex lock protections(V2)

As these operations are performed in hardware setup and there is actually no race conditions during this period considering:
1. the hardware setup is serial and cannnot be in parallel 2. all other operations can be performed only after hardware
   setup complete.

V2: rich the commit log description

Change-Id: I096d7ab0855ff59b0ecb56fd9d6d9946b3605fc8
Signed-off-by: Evan Quan <evan.quan at amd.com>
---
 drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c      | 4 ----
 drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c | 2 --
 2 files changed, 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
index 09dc5303762b..b7cad8ef6153 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
@@ -361,20 +361,16 @@ static int smu_get_driver_allowed_feature_mask(struct smu_context *smu)
 int ret = 0;
 uint32_t allowed_feature_mask[SMU_FEATURE_MAX/32];

-mutex_lock(&feature->mutex);
 bitmap_zero(feature->allowed, SMU_FEATURE_MAX);
-mutex_unlock(&feature->mutex);

 ret = smu_get_allowed_feature_mask(smu, allowed_feature_mask,
      SMU_FEATURE_MAX/32);
 if (ret)
 return ret;

-mutex_lock(&feature->mutex);
 bitmap_or(feature->allowed, feature->allowed,
       (unsigned long *)allowed_feature_mask,
       feature->feature_num);
-mutex_unlock(&feature->mutex);

 return ret;
 }
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
index 548db1edd352..28a19ffd22a1 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
@@ -721,7 +721,6 @@ int smu_v11_0_set_allowed_mask(struct smu_context *smu)
 int ret = 0;
 uint32_t feature_mask[2];

-mutex_lock(&feature->mutex);
 if (bitmap_empty(feature->allowed, SMU_FEATURE_MAX) || feature->feature_num < 64)
 goto failed;

@@ -738,7 +737,6 @@ int smu_v11_0_set_allowed_mask(struct smu_context *smu)
 goto failed;

 failed:
-mutex_unlock(&feature->mutex);
 return ret;
 }

--
2.28.0