lkml.org 
[lkml]   [2021]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 7/9] scsi: ufs: Let host_sem cover the entire system suspend/resume
Hi Adrian,

On 2021-06-10 21:32, Adrian Hunter wrote:
> 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()?

I intend to make it this (simple) way - if error handling is invoked
during system suspend/resume, it should just wait until system resume
is finished. suspend/resume does not count on error handling, if
suspend/resume
run into errors, they just fail and bail.

>
> Wouldn't this complexity go away if we just did recovery
> directly in __ufshcd_wl_suspend() and __ufshcd_wl_resume()?
>

Please kindly check my reply in patch #5.

Thanks,
Can Guo.

>>
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> ---
>> 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
>>

\
 
 \ /
  Last update: 2021-06-11 05:09    [W:0.071 / U:0.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site