| Message ID | cover.1619223249.git.asutoshd@codeaurora.org |
|---|---|
| Headers | show |
| Series | Enable power management for ufs wlun | expand |
On 24/04/21 3:20 am, Asutosh Das wrote: > During runtime-suspend of ufs host, the scsi devices are > already suspended and so are the queues associated with them. > But the ufs host sends SSU (START_STOP_UNIT) to wlun > during its runtime-suspend. > During the process blk_queue_enter checks if the queue is not in > suspended state. If so, it waits for the queue to resume, and never > comes out of it. > The commit > (d55d15a33: scsi: block: Do not accept any requests while suspended) > adds the check if the queue is in suspended state in blk_queue_enter(). > > Call trace: > __switch_to+0x174/0x2c4 > __schedule+0x478/0x764 > schedule+0x9c/0xe0 > blk_queue_enter+0x158/0x228 > blk_mq_alloc_request+0x40/0xa4 > blk_get_request+0x2c/0x70 > __scsi_execute+0x60/0x1c4 > ufshcd_set_dev_pwr_mode+0x124/0x1e4 > ufshcd_suspend+0x208/0x83c > ufshcd_runtime_suspend+0x40/0x154 > ufshcd_pltfrm_runtime_suspend+0x14/0x20 > pm_generic_runtime_suspend+0x28/0x3c > __rpm_callback+0x80/0x2a4 > rpm_suspend+0x308/0x614 > rpm_idle+0x158/0x228 > pm_runtime_work+0x84/0xac > process_one_work+0x1f0/0x470 > worker_thread+0x26c/0x4c8 > kthread+0x13c/0x320 > ret_from_fork+0x10/0x18 > > Fix this by registering ufs device wlun as a scsi driver and > registering it for block runtime-pm. Also make this as a > supplier for all other luns. That way, this device wlun > suspends after all the consumers and resumes after > hba resumes. This also registers a new scsi driver for rpmb wlun. > This new driver is mostly used to clear rpmb uac. > > Fixed smatch warnings: > Reported-by: kernel test robot <lkp@intel.com> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > Co-developed-by: Can Guo <cang@codeaurora.org> > Signed-off-by: Can Guo <cang@codeaurora.org> > Signed-off-by: Asutosh Das <asutoshd@codeaurora.org> Note we don't use regulators, clocks, clock scaling or gating. Although those things do look OK. Notwithstanding that: Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Asutosh,
> This patch attempts to fix a deadlock in ufs while sending SSU.
Applied to 5.14/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
> Asutosh, In several places there is now a reference: "Also check the description of __ufshcd_wl_suspend()" But no such description is to found. Might want to add it in a supplementary patch? Thanks, Avri > > > This patch attempts to fix a deadlock in ufs while sending SSU. > > Applied to 5.14/scsi-staging, thanks! > > -- > Martin K. Petersen Oracle Linux Engineering
On Fri, 23 Apr 2021 17:20:15 -0700, 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. > > [...] Applied to 5.14/scsi-queue, thanks! [1/2] scsi: ufs: Enable power management for wlun https://git.kernel.org/mkp/scsi/c/b294ff3e3449 [2/2] ufs: sysfs: Resume the proper scsi device https://git.kernel.org/mkp/scsi/c/aef80fd1da32 -- Martin K. Petersen Oracle Linux Engineering
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 v20 -> v21: - Addressed Adrian's comments v19 -> v20: - Addressed Adrian's comments - Addressed Bart's comments v18 -> v19: - Addressed Adrian's comments - Fixed smatch warnings v17 -> v18: - Addressed Adrian's comments v16 -> v17: - Addressed Adrian's & Daejun's comments v15 -> v16: - Brought back the missing changes * Added scsi_autopm_[get/put] to ufs_debugfs[get/put]_user_access() * Fix ufshcd_wl_poweroff() v14 -> v15: - Rebased on 5.13/scsi-staging v13 -> v14: - Addressed Adrian's comments * Rebased it on top of scsi-next * Added scsi_autopm_[get/put] to ufs_debugfs[get/put]_user_access() * Resume the device in ufshcd_remove() * Unregister ufs_rpmb_wlun before ufs_dev_wlun * hba->shutting_down moved to ufshcd_wl_shutdown() 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 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 | 6 +- 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 | 24 +- drivers/scsi/ufs/ufs_bsg.c | 6 +- drivers/scsi/ufs/ufshcd-pci.c | 36 +- drivers/scsi/ufs/ufshcd.c | 700 ++++++++++++++++++++++++++----------- drivers/scsi/ufs/ufshcd.h | 33 ++ include/trace/events/ufs.h | 20 ++ 14 files changed, 585 insertions(+), 264 deletions(-)