Messages in this thread | | | Subject | Re: [PATCH v12 1/2] scsi: ufs: Enable power management for wlun | From | "Asutosh Das (asd)" <> | Date | Fri, 19 Mar 2021 08:08:35 -0700 |
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On 3/18/2021 8:12 PM, Bart Van Assche wrote: > On 3/18/21 5:35 PM, 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 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(). > Hi Bart, Thanks for the review comments.
> What is the role of the WLUN during runtime suspend and why does a > command need to be sent to the WLUN during runtime suspend? Although it > is possible to derive this from the source code, please explain this in > the patch description. > Ok. Will explain it in the next version.
> What does the acronym SSU stand for? This doesn't seem like a commonly > used kernel acronym to me so please expand that acronym. > START STOP UNIT. Anyway, I'll expand it in the next version.
>> 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. > > That's an interesting solution. > >> -void __exit ufs_debugfs_exit(void) >> +void ufs_debugfs_exit(void) > > Is the above change related to the rest of this patch? > Yes, it's used to handle an error in ufshcd_core_init() function.
>> static struct platform_driver ufs_qcom_pltform = { >> diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c >> index 5b2bc1a..cbb5a90 100644 >> --- a/drivers/scsi/ufs/ufs_bsg.c >> +++ b/drivers/scsi/ufs/ufs_bsg.c >> @@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job) >> >> bsg_reply->reply_payload_rcv_len = 0; >> >> - pm_runtime_get_sync(hba->dev); >> + scsi_autopm_get_device(hba->sdev_ufs_device); > > Can the pm_runtime_get_sync() to scsi_autopm_get_device() changes be > moved into a separate patch? > I guess so. But then this patch would have issues when used independently.
>> +static inline bool is_rpmb_wlun(struct scsi_device *sdev) >> +{ >> + return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN)); >> +} > > Has this patch been verified with checkpatch? Checkpatch should have > reported the following for the above code: > > return is not a function, parentheses are not required > Yes, it has been verified. But I didn't see any error reports. Below is the o/p of checkpatch:
$ ./scripts/checkpatch.pl /tmp/up/ufs-pm-v12/* ------------------------------------------ /tmp/up/ufs-pm-v12/0000-cover-letter.patch ------------------------------------------ WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line) #107: Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
total: 0 errors, 1 warnings, 0 lines checked
NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace.
/tmp/up/ufs-pm-v12/0000-cover-letter.patch has style problems, please review. ----------------------------------------------------------------------- /tmp/up/ufs-pm-v12/0001-scsi-ufs-Enable-power-management-for-wlun.patch ----------------------------------------------------------------------- total: 0 errors, 0 warnings, 1180 lines checked
/tmp/up/ufs-pm-v12/0001-scsi-ufs-Enable-power-management-for-wlun.patch has no obvious style problems and is ready for submission. --------------------------------------------------------------------- /tmp/up/ufs-pm-v12/0002-ufs-sysfs-Resume-the-proper-scsi-device.patch --------------------------------------------------------------------- total: 0 errors, 0 warnings, 91 lines checked
/tmp/up/ufs-pm-v12/0002-ufs-sysfs-Resume-the-proper-scsi-device.patch has no obvious style problems and is ready for submission.
NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS.
>> +static inline bool is_device_wlun(struct scsi_device *sdev) >> +{ >> + return (sdev->lun == >> + ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN)); >> +} > > Same comment here. > >> /* >> - * Don't assume anything of pm_runtime_get_sync(), if >> + * Don't assume anything of resume, if >> * resume fails, irq and clocks can be OFF, and powers >> * can be OFF or in LPM. >> */ > > Please make better use of the horizontal space in the above comment by > making comment lines longer. > Ok Sure.
> Thanks, > > Bart. >
-asd
-- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, Linux Foundation Collaborative Project
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