Re: [PATCH v13 0/2] Enable power management for ufs wlun

["Asutosh Das (asd)" <asutoshd@codeaurora.org>]

On 3/24/2021 6:39 PM, Asutosh Das wrote:
> This patch attempts to fix a deadlock in ufs while sending SSU.
> Recently, blk_queue_enter() added a check to not process requests if the
> queue is suspended. That leads to a resume of the associated device which
> is suspended. In ufs, that device is ufs device wlun and it's parent is
> ufs_hba. This resume tries to resume ufs device wlun which in turn tries
> to resume ufs_hba, which is already in the process of suspending, thus
> causing a deadlock.
> 
> This patch takes care of:
> * Suspending the ufs device lun only after all other luns are suspended
> * Sending SSU during ufs device wlun suspend
> * Clearing uac for rpmb and ufs device wlun
> * Not sending commands to the device during host suspend
> 
> v12 -> v13:
> - Addressed Adrian's comments
>    * Paired pm_runtime_get_noresume() with pm_runtime_put()
>    * no rpm_autosuspend for ufs device wlun
>    * Moved runtime-pm init functionality to ufshcd_wl_probe()
> - Addressed Bart's comments
>    * Expanded abbrevs in commit message
> 

Hi Adrian
I did a limited testing on your fix in the pm framework along with this 
v13 patchset. I couldn't reproduce the issue.

I'd appreciate if you can please take a look at the v13 changes.
If all looks good in that, I'd do an extensive testing.

Thanks,
-asd

> v11 -> v12:
> - Addressed Adrian's comments
>    * Fixed ahit for Mediatek driver
>    * Fixed error handling in ufshcd_core_init()
>    * Tested this patch and the issue is still seen.
> 
> v10 -> v11:
> - Fixed supplier suspending before consumer race
> - Addressed Adrian's comments
>    * Added proper resume/suspend cb to ufshcd_auto_hibern8_update()
>    * Cosmetic changes to ufshcd-pci.c
>    * Cleaned up ufshcd_system_suspend()
>    * Added ufshcd_debugfs_eh_exit to ufshcd_core_init()
> 
> v9 -> v10:
> - Addressed Adrian's comments
>    * Moved suspend/resume vops to __ufshcd_wl_[suspend/resume]()
>    * Added correct resume in ufs_bsg
> 
> v8 -> v9:
> - Addressed Adrian's comments
>    * Moved link transition to __ufshcd_wl_[suspend/resume]()
>    * Fixed the other minor comments
> 
> v7 -> v8:
> - Addressed Adrian's comments
>    * Removed separate autosuspend delay for ufs-device lun
>    * Fixed the ee handler getting scheduled during pm
>    * Always runtime resume in suspend_prepare()
>    * Added CONFIG_PM_SLEEP where needed
>    
> v6 -> v7:
>    * Resume the ufs device before shutting it down
> 
> v5 -> v6:
> - Addressed Adrian's comments
>    * Added complete() cb
>    * Added suspend_prepare() and complete() to all drivers
>    * Moved suspend_prepare() and complete() to ufshcd
>    * .poweroff() uses ufhcd_wl_poweroff()
>    * Removed several forward declarations
>    * Moved scsi_register_driver() to ufshcd_core_init()
> 
> v4 -> v5:
> - Addressed Adrian's comments
>    * Used the rpmb driver contributed by Adrian
>    * Runtime-resume the ufs device during suspend to honor spm-lvl
>    * Unregister the scsi_driver in ufshcd_remove()
>    * Currently shutdown() puts the ufs device to power-down mode
>      so, just removed ufshcd_pci_poweroff()
>    * Quiesce the scsi device during shutdown instead of remove
> 
> v3 RFC -> v4:
> - Addressed Bart's comments
>    * Except that I didn't get any checkpatch failures
> - Addressed Avri's comments
> - Addressed Adrian's comments
>    * Added a check for deepsleep power mode
>    * Removed a couple of forward declarations
>    * Didn't separate the scsi drivers because in rpmb case it just sends uac
>      in resume and it seemed pretty neat to me.
> - Added sysfs changes to resume the devices before accessing
> 
> Asutosh Das (2):
>    scsi: ufs: Enable power management for wlun
>    ufs: sysfs: Resume the proper scsi device
> 
>   drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
>   drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
>   drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
>   drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
>   drivers/scsi/ufs/ufs-exynos.c      |   2 +
>   drivers/scsi/ufs/ufs-hisi.c        |   2 +
>   drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
>   drivers/scsi/ufs/ufs-qcom.c        |   2 +
>   drivers/scsi/ufs/ufs-sysfs.c       |  30 +-
>   drivers/scsi/ufs/ufs_bsg.c         |   6 +-
>   drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
>   drivers/scsi/ufs/ufshcd.c          | 627 ++++++++++++++++++++++++++-----------
>   drivers/scsi/ufs/ufshcd.h          |   6 +
>   include/trace/events/ufs.h         |  20 ++
>   14 files changed, 513 insertions(+), 238 deletions(-)
> 


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