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| author | Can Guo <cang@codeaurora.org> | 2020-09-22 00:09:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-30 11:25:38 +0100 |
| commit | a0e74c97fe3f0affa3d1d9f0527894e153c1605a (patch) | |
| tree | a4daeb160314607d186b3b4362e6a51c2203f901 /drivers/scsi/ufs | |
| parent | 3e25867ac4168fd56d67dd5c34c4cab8f5f3948d (diff) | |
| download | linux-stable-a0e74c97fe3f0affa3d1d9f0527894e153c1605a.tar.gz linux-stable-a0e74c97fe3f0affa3d1d9f0527894e153c1605a.tar.bz2 linux-stable-a0e74c97fe3f0affa3d1d9f0527894e153c1605a.zip | |
scsi: ufs: Make sure clk scaling happens only when HBA is runtime ACTIVE
[ Upstream commit 73cc291c270248567245f084dcdf5078069af6b5 ]
If someone plays with the UFS clk scaling devfreq governor through sysfs,
ufshcd_devfreq_scale may be called even when HBA is not runtime ACTIVE.
This can lead to unexpected error. We cannot just protect it by calling
pm_runtime_get_sync() because that may cause a race condition since HBA
runtime suspend ops need to suspend clk scaling. To fix this call
pm_runtime_get_noresume() and check HBA's runtime status. Only proceed if
HBA is runtime ACTIVE, otherwise just bail.
governor_store
devfreq_performance_handler
update_devfreq
devfreq_set_target
ufshcd_devfreq_target
ufshcd_devfreq_scale
Link: https://lore.kernel.org/r/1600758548-28576-1-git-send-email-cang@codeaurora.org
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/scsi/ufs')
| -rw-r--r-- | drivers/scsi/ufs/ufshcd.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 7e4e6e982055..61b1eae42ea8 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1281,8 +1281,15 @@ static int ufshcd_devfreq_target(struct device *dev, } spin_unlock_irqrestore(hba->host->host_lock, irq_flags); + pm_runtime_get_noresume(hba->dev); + if (!pm_runtime_active(hba->dev)) { + pm_runtime_put_noidle(hba->dev); + ret = -EAGAIN; + goto out; + } start = ktime_get(); ret = ufshcd_devfreq_scale(hba, scale_up); + pm_runtime_put(hba->dev); trace_ufshcd_profile_clk_scaling(dev_name(hba->dev), (scale_up ? "up" : "down"), |