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* [PATCH v9 0/2] Enable power management for ufs wlun
@ 2021-03-02  3:21 ` Asutosh Das
  0 siblings, 0 replies; 12+ messages in thread
From: Asutosh Das @ 2021-03-02  3:21 UTC (permalink / raw)
  To: cang, martin.petersen, adrian.hunter, linux-scsi
  Cc: Asutosh Das, linux-arm-msm, Matthias Brugger,
	moderated list:ARM/Mediatek SoC support,
	moderated list:ARM/Mediatek SoC support

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

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-exynos.c      |   2 +
 drivers/scsi/ufs/ufs-hisi.c        |   2 +
 drivers/scsi/ufs/ufs-mediatek.c    |   2 +
 drivers/scsi/ufs/ufs-qcom.c        |   2 +
 drivers/scsi/ufs/ufs-sysfs.c       |  26 +-
 drivers/scsi/ufs/ufshcd-pci.c      |  32 +-
 drivers/scsi/ufs/ufshcd.c          | 609 +++++++++++++++++++++++++++----------
 drivers/scsi/ufs/ufshcd.h          |   7 +
 include/trace/events/ufs.h         |  20 ++
 11 files changed, 508 insertions(+), 198 deletions(-)

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.


^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2021-03-03 20:29 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-02  3:21 [PATCH v9 0/2] Enable power management for ufs wlun Asutosh Das
2021-03-02  3:21 ` Asutosh Das
2021-03-02  3:21 ` Asutosh Das
2021-03-02  3:21 ` [PATCH v9 1/2] scsi: ufs: Enable power management for wlun Asutosh Das
2021-03-02  3:21   ` Asutosh Das
2021-03-02  3:21   ` Asutosh Das
2021-03-02 14:14   ` Adrian Hunter
2021-03-02 14:14     ` Adrian Hunter
2021-03-02 14:14     ` Adrian Hunter
2021-03-02 16:20     ` Asutosh Das
2021-03-02 16:20       ` Asutosh Das
2021-03-02  3:21 ` [PATCH v9 2/2] ufs: sysfs: Resume the proper scsi device Asutosh Das

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