scsi: ufs: Make sure clk scaling happens only when HBA is runtime ACTIVE
[ Upstream commit 73cc291c27
]
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>
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@ -1257,8 +1257,15 @@ static int ufshcd_devfreq_target(struct device *dev,
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}
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}
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spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
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spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
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pm_runtime_get_noresume(hba->dev);
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if (!pm_runtime_active(hba->dev)) {
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pm_runtime_put_noidle(hba->dev);
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ret = -EAGAIN;
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goto out;
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}
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start = ktime_get();
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start = ktime_get();
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ret = ufshcd_devfreq_scale(hba, scale_up);
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ret = ufshcd_devfreq_scale(hba, scale_up);
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pm_runtime_put(hba->dev);
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trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
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trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
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(scale_up ? "up" : "down"),
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(scale_up ? "up" : "down"),
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