| Message ID | 1408023067-26103-8-git-send-email-draviv@codeaurora.org (mailing list archive) |
|---|---|
| State | Deferred |
| Headers | show |
On Thu, Aug 14, 2014 at 04:30:58PM +0300, Dolev Raviv wrote: > From: Subhash Jadavani <subhashj@codeaurora.org> > > REPORT LUNS command has "SELECT REPORT" field which controls what type of > logical units to be reported by device server. According to UFS device > standard, if this field is set to 0, REPORT LUNS would report only report > standard logical units. If it's set to 1 then it would report only well > known logical unit and if it's set to 2 then device would report both > standard and well known logical units. > Some well-known logical units might not have scsi upper-layer drivers. In > such cases, the runtime PM reference count increased during device > enumeration will not be decreased, causing the parent device (host) to > always be on even during idle. > > This change allows the SCSI LLD (Low Level Driver) to choose which type > of logical units should be detected. > > Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> > Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org> > Signed-off-by: Dolev Raviv <draviv@codeaurora.org> > > diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c > index 4a6e4ba..5a0e164 100644 > --- a/drivers/scsi/scsi_scan.c > +++ b/drivers/scsi/scsi_scan.c > @@ -802,6 +802,14 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, > } else { > sdev->type = (inq_result[0] & 0x1f); > sdev->removable = (inq_result[1] & 0x80) >> 7; > + > + /* > + * some devices may respond with wrong type for > + * well-known logical units. Force well-known type > + * to enumerate them correctly. > + */ > + if (scsi_is_wlun(sdev->lun) && (sdev->type != TYPE_WLUN)) > + sdev->type = TYPE_WLUN; no need to test for TYPE_WLUN here. > switch (sdev->type) { > @@ -817,6 +825,7 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, > case TYPE_COMM: > case TYPE_RAID: > case TYPE_OSD: > + case TYPE_WLUN: > sdev->writeable = 1; > break; > case TYPE_ROM: This switch statements has been removed in 3.17-rc1, please rebase your series on top of it. While you're at it please make this patch, which introduce? core scsi changes first in the series. > @@ -1412,6 +1421,13 @@ static int scsi_report_lun_scan(struct scsi_target *starget, int bflags, > */ > memset(&scsi_cmd[1], 0, 5); > > + if (shost->report_wlus) > + /* > + * Set "SELECT REPORT" field to 0x2 which will make device to > + * report well known logical units along with standard LUs. > + */ > + scsi_cmd[2] = 0x2; So we're finally getting well known LUN support. I think we should key this off the SBC compliance level and not have the drivers opt in. > diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c > index 5f36788..ba9d0f0 100644 > --- a/drivers/scsi/scsi_sysfs.c > +++ b/drivers/scsi/scsi_sysfs.c > @@ -1060,6 +1060,13 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev) > } > } > > + /* > + * put runtime pm reference for well-known logical units, > + * drivers are expected to _get_* again during probe. > + */ > + if (scsi_is_wlun(sdev->lun)) > + scsi_autopm_put_device(sdev); Special casing the well known LUNs here seems wrong. Shouldn't we do this for any devices that don't get a driver attached to them? -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>>> "Christoph" == Christoph Hellwig <hch@infradead.org> writes: >> + /* >> + * put runtime pm reference for well-known logical units, >> + * drivers are expected to _get_* again during probe. >> + */ >> + if (scsi_is_wlun(sdev->lun)) >> + scsi_autopm_put_device(sdev); Christoph> Special casing the well known LUNs here seems wrong. Christoph> Shouldn't we do this for any devices that don't get a driver Christoph> attached to them? That would also be my preference. Relying on WLU for this seems like a kludge.
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 4a6e4ba..5a0e164 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -802,6 +802,14 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, } else { sdev->type = (inq_result[0] & 0x1f); sdev->removable = (inq_result[1] & 0x80) >> 7; + + /* + * some devices may respond with wrong type for + * well-known logical units. Force well-known type + * to enumerate them correctly. + */ + if (scsi_is_wlun(sdev->lun) && (sdev->type != TYPE_WLUN)) + sdev->type = TYPE_WLUN; } switch (sdev->type) { @@ -817,6 +825,7 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, case TYPE_COMM: case TYPE_RAID: case TYPE_OSD: + case TYPE_WLUN: sdev->writeable = 1; break; case TYPE_ROM: @@ -1412,6 +1421,13 @@ static int scsi_report_lun_scan(struct scsi_target *starget, int bflags, */ memset(&scsi_cmd[1], 0, 5); + if (shost->report_wlus) + /* + * Set "SELECT REPORT" field to 0x2 which will make device to + * report well known logical units along with standard LUs. + */ + scsi_cmd[2] = 0x2; + /* * bytes 6 - 9: length of the command. */ diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 5f36788..ba9d0f0 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1060,6 +1060,13 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev) } } + /* + * put runtime pm reference for well-known logical units, + * drivers are expected to _get_* again during probe. + */ + if (scsi_is_wlun(sdev->lun)) + scsi_autopm_put_device(sdev); + return error; } diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h index 91e2e42..6a9b102 100644 --- a/include/scsi/scsi.h +++ b/include/scsi/scsi.h @@ -332,6 +332,7 @@ static inline int scsi_status_is_good(int status) #define TYPE_ENCLOSURE 0x0d /* Enclosure Services Device */ #define TYPE_RBC 0x0e #define TYPE_OSD 0x11 +#define TYPE_WLUN 0x1e /* well-known logical unit */ #define TYPE_NO_LUN 0x7f /* SCSI protocols; these are taken from SPC-3 section 7.5 */ diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index b2bc519..05664c4 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -675,6 +675,11 @@ struct Scsi_Host { unsigned no_write_same:1; /* + * Set "SELECT REPORT" field to allow detection of well known logical + * units along with standard LUs. + */ + unsigned report_wlus:1; + /* * Optional work queue to be utilized by the transport */ char work_q_name[20];