| Message ID | 1442155977-7686-17-git-send-email-ygardi@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2015-09-13 23:52 GMT+09:00 Yaniv Gardi <ygardi@codeaurora.org>: > We put the UFS device in sleep state & UFS link in hibern8 state during > runtime suspaned. After this we put all the UFS rails in low power > modes immediately but it seems some devices may still draw more than > sleep current from UFS rails (especially from VCCQ rail) atleast for > 500us. > To avoid this situation, this change adds 2ms delay before putting > these UFS rails in LPM mode. > > Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> > Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org> > > --- > drivers/scsi/ufs/ufshcd.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 20b4c0e..786df28 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -5694,6 +5694,15 @@ out: > static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) > { > /* > + * It seems some UFS devices may keep drawing more than sleep current > + * (atleast for 500us) from UFS rails (especially from VCCQ rail). > + * To avoid this situation, add 2ms delay before putting these UFS > + * rails in LPM mode. > + */ > + if (!ufshcd_is_link_active(hba)) > + usleep_range(2000, 2100); > + Shouldn't we define dev_quirks for this? > + /* > * If UFS device is either in UFS_Sleep turn off VCC rail to save some > * power. > * > -- > 1.8.5.2 > > -- > QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> 2015-09-13 23:52 GMT+09:00 Yaniv Gardi <ygardi@codeaurora.org>: >> We put the UFS device in sleep state & UFS link in hibern8 state during >> runtime suspaned. After this we put all the UFS rails in low power >> modes immediately but it seems some devices may still draw more than >> sleep current from UFS rails (especially from VCCQ rail) atleast for >> 500us. >> To avoid this situation, this change adds 2ms delay before putting >> these UFS rails in LPM mode. >> >> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> >> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org> >> >> --- >> drivers/scsi/ufs/ufshcd.c | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >> index 20b4c0e..786df28 100644 >> --- a/drivers/scsi/ufs/ufshcd.c >> +++ b/drivers/scsi/ufs/ufshcd.c >> @@ -5694,6 +5694,15 @@ out: >> static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) >> { >> /* >> + * It seems some UFS devices may keep drawing more than sleep >> current >> + * (atleast for 500us) from UFS rails (especially from VCCQ >> rail). >> + * To avoid this situation, add 2ms delay before putting these >> UFS >> + * rails in LPM mode. >> + */ >> + if (!ufshcd_is_link_active(hba)) >> + usleep_range(2000, 2100); >> + > > Shouldn't we define dev_quirks for this? as you suggested, in v2 i added a device quirk for that. > >> + /* >> * If UFS device is either in UFS_Sleep turn off VCC rail to >> save some >> * power. >> * >> -- >> 1.8.5.2 >> >> -- >> QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a >> member of Code Aurora Forum, hosted by The Linux Foundation >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 20b4c0e..786df28 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5694,6 +5694,15 @@ out: static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) { /* + * It seems some UFS devices may keep drawing more than sleep current + * (atleast for 500us) from UFS rails (especially from VCCQ rail). + * To avoid this situation, add 2ms delay before putting these UFS + * rails in LPM mode. + */ + if (!ufshcd_is_link_active(hba)) + usleep_range(2000, 2100); + + /* * If UFS device is either in UFS_Sleep turn off VCC rail to save some * power. *