Re: [PATCH v3 7/9] scsi: ufs: Let host_sem cover the entire system suspend/resume
From: Adrian Hunter <adrian.hunter@intel.com>
Date: 2021-06-10 13:35:01
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On 10/06/21 7:43 am, Can Guo wrote:
UFS error handling now is doing more than just re-probing, but also sending scsi cmds, e.g., for clearing UACs, and recovering runtime PM error, which may change runtime status of scsi devices. To protect system suspend/resume from being disturbed by error handling, move the host_sem from wl pm ops to ufshcd_suspend_prepare() and ufshcd_resume_complete().
Have you checked whether error handling might actually be needed after ufshcd_suspend_prepare()? Wouldn't this complexity go away if we just did recovery directly in __ufshcd_wl_suspend() and __ufshcd_wl_resume()?
quoted hunk ↗ jump to hunk
Signed-off-by: Can Guo <redacted> --- drivers/scsi/ufs/ufshcd.c | 8 +++----- drivers/scsi/ufs/ufshcd.h | 2 +- 2 files changed, 4 insertions(+), 6 deletions(-)diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index c418a19..861942b 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c@@ -9060,16 +9060,13 @@ static int ufshcd_wl_suspend(struct device *dev) ktime_t start = ktime_get(); hba = shost_priv(sdev->host); - down(&hba->host_sem); if (pm_runtime_suspended(dev)) goto out; ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM); - if (ret) { + if (ret) dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret); - up(&hba->host_sem); - } out: if (!ret)@@ -9102,7 +9099,6 @@ static int ufshcd_wl_resume(struct device *dev) hba->curr_dev_pwr_mode, hba->uic_link_state); if (!ret) hba->is_wl_sys_suspended = false; - up(&hba->host_sem); return ret; } #endif@@ -9665,6 +9661,7 @@ void ufshcd_resume_complete(struct device *dev) ufshcd_rpmb_rpm_put(hba); hba->rpmb_complete_put = false; } + up(&hba->host_sem); } EXPORT_SYMBOL_GPL(ufshcd_resume_complete);@@ -9691,6 +9688,7 @@ int ufshcd_suspend_prepare(struct device *dev) ufshcd_rpmb_rpm_get_sync(hba); hba->rpmb_complete_put = true; } + down(&hba->host_sem); return 0; } EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index eaebb4e..47da47c 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h@@ -693,7 +693,7 @@ struct ufs_hba_monitor { * @ee_ctrl_mask: Exception event control mask * @is_powered: flag to check if HBA is powered * @shutting_down: flag to check if shutdown has been invoked - * @host_sem: semaphore used to serialize concurrent contexts + * @host_sem: semaphore used to avoid concurrency of contexts * @eh_wq: Workqueue that eh_work works on * @eh_work: Worker to handle UFS errors that require s/w attention * @eeh_work: Worker to handle exception events