Please add proper lock in smu_set_soft_freq_range() then.
You can do necessary modification to existing code paths.
Otherwise without lock protection, you may run into race condition on the new debugfs intrace(amdgpu_debugfs_sclk_set) called by multiple instances.
-----Original Message-----
From: Gui, Jack <Jack.Gui@xxxxxxx>
Sent: Friday, February 28, 2020 12:35 PM
To: Quan, Evan <Evan.Quan@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Feng, Kenneth <Kenneth.Feng@xxxxxxx>; Xu, Feifei <Feifei.Xu@xxxxxxx>
Subject: RE: [PATCH 2/2] drm/amdgpu: Add debugfs interface to set arbitrary sclk for navi14
[AMD Official Use Only - Internal Distribution Only]
Hi Evan,
No lock is created for smu_set_soft_freq_range() in this code path.
But some other sysfs interfaces calling smu_set_soft_freq_range() indirectly have created lock in middle function to protect smu_set_soft_freq_range() as critical resource.
So, if we want to lock the "issue message action" in smu_set_soft_freq_range(), another patch is needed.
BR,
Jack
-----Original Message-----
From: Quan, Evan <Evan.Quan@xxxxxxx>
Sent: Friday, February 28, 2020 11:37 AM
To: Gui, Jack <Jack.Gui@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Feng, Kenneth <Kenneth.Feng@xxxxxxx>; Xu, Feifei <Feifei.Xu@xxxxxxx>; Gui, Jack <Jack.Gui@xxxxxxx>
Subject: RE: [PATCH 2/2] drm/amdgpu: Add debugfs interface to set arbitrary sclk for navi14
Please confirm whether smu_set_soft_freq_range() is properly lock protected.
-----Original Message-----
From: Chengming Gui <Jack.Gui@xxxxxxx>
Sent: Friday, February 28, 2020 10:37 AM
To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Quan, Evan <Evan.Quan@xxxxxxx>; Feng, Kenneth <Kenneth.Feng@xxxxxxx>; Xu, Feifei <Feifei.Xu@xxxxxxx>; Gui, Jack <Jack.Gui@xxxxxxx>
Subject: [PATCH 2/2] drm/amdgpu: Add debugfs interface to set arbitrary sclk for navi14
add debugfs interface amdgpu_force_sclk
to set arbitrary sclk for navi14
Signed-off-by: Chengming Gui <Jack.Gui@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 44 ++++++++++++++++++++++++++
drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h | 3 ++
2 files changed, 47 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 3bb7405..5ee7e92 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1269,9 +1269,43 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)
return 0;
}
+static int amdgpu_debugfs_sclk_set(void *data, u64 val) {
+ int ret = 0;
+ uint32_t max_freq, min_freq;
+ struct amdgpu_device *adev = (struct amdgpu_device *)data;
+
+ if (amdgpu_sriov_vf(adev) && !amdgpu_sriov_is_pp_one_vf(adev))
+ return -EINVAL;
+
+ ret = pm_runtime_get_sync(adev->ddev->dev);
+ if (ret < 0)
+ return ret;
+
+ if (is_support_sw_smu(adev)) {
+ ret = smu_get_dpm_freq_range(&adev->smu, SMU_SCLK, &min_freq, &max_freq, true);
+ if (ret || val > max_freq || val < min_freq)
+ return -EINVAL;
+ ret = smu_set_soft_freq_range(&adev->smu, SMU_SCLK, (uint32_t)val, (uint32_t)val);
+ } else {
+ return 0;
+ }
+
+ pm_runtime_mark_last_busy(adev->ddev->dev);
+ pm_runtime_put_autosuspend(adev->ddev->dev);
+
+ if (ret)
+ return -EINVAL;
+
+ return 0;
+}
+
DEFINE_SIMPLE_ATTRIBUTE(fops_ib_preempt, NULL,
amdgpu_debugfs_ib_preempt, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_sclk_set, NULL,
+ amdgpu_debugfs_sclk_set, "%llu\n");
+
int amdgpu_debugfs_init(struct amdgpu_device *adev) {
int r, i;
@@ -1285,6 +1319,15 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)
return -EIO;
}
+ adev->smu.debugfs_sclk =
+ debugfs_create_file("amdgpu_force_sclk", 0200,
+ adev->ddev->primary->debugfs_root, adev,
+ &fops_sclk_set);
+ if (!(adev->smu.debugfs_sclk)) {
+ DRM_ERROR("unable to create amdgpu_set_sclk debugsfs file\n");
+ return -EIO;
+ }
+
/* Register debugfs entries for amdgpu_ttm */
r = amdgpu_ttm_debugfs_init(adev);
if (r) {
@@ -1353,6 +1396,7 @@ void amdgpu_debugfs_fini(struct amdgpu_device *adev)
}
amdgpu_ttm_debugfs_fini(adev);
debugfs_remove(adev->debugfs_preempt);
+ debugfs_remove(adev->smu.debugfs_sclk);
}
#else
diff --git a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
index 97b6714..36fe19c 100644
--- a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
+++ b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
@@ -371,6 +371,9 @@ struct smu_context
struct amd_pp_display_configuration *display_config;
struct smu_baco_context smu_baco;
void *od_settings;
+#if defined(CONFIG_DEBUG_FS)
+ struct dentry *debugfs_sclk;
+#endif
uint32_t pstate_sclk;
uint32_t pstate_mclk;
--
2.7.4
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