From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH/RFC V2 07/16] scsi: support well known logical units Date: Tue, 19 Aug 2014 12:22:51 -0500 Message-ID: <20140819172251.GA12892@infradead.org> References: <1408023067-26103-1-git-send-email-draviv@codeaurora.org> <1408023067-26103-8-git-send-email-draviv@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from casper.infradead.org ([85.118.1.10]:41381 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753550AbaHSRUh (ORCPT ); Tue, 19 Aug 2014 13:20:37 -0400 Content-Disposition: inline In-Reply-To: <1408023067-26103-8-git-send-email-draviv@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Dolev Raviv Cc: James.Bottomley@HansenPartnership.com, hch@infradead.org, linux-scsi@vger.kernel.org, linux-scsi-owner@vger.kernel.org, linux-arm-msm@vger.kernel.org, santoshsy@gmail.com, Subhash Jadavani , Sujit Reddy Thumma , Hannes Reinecke , "Martin K. Petersen" On Thu, Aug 14, 2014 at 04:30:58PM +0300, Dolev Raviv wrote: > From: Subhash Jadavani >=20 > REPORT LUNS command has "SELECT REPORT" field which controls what typ= e of > logical units to be reported by device server. According to UFS devic= e > standard, if this field is set to 0, REPORT LUNS would report only re= port > standard logical units. If it's set to 1 then it would report only we= ll > 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= =2E In > such cases, the runtime PM reference count increased during device > enumeration will not be decreased, causing the parent device (host) t= o > always be on even during idle. >=20 > This change allows the SCSI LLD (Low Level Driver) to choose which ty= pe > of logical units should be detected. >=20 > Signed-off-by: Subhash Jadavani > Signed-off-by: Sujit Reddy Thumma > Signed-off-by: Dolev Raviv >=20 > 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 =3D (inq_result[0] & 0x1f); > sdev->removable =3D (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 !=3D TYPE_WLUN)) > + sdev->type =3D 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 =3D 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=D1=95 core scsi changes first in the series. > @@ -1412,6 +1421,13 @@ static int scsi_report_lun_scan(struct scsi_ta= rget *starget, int bflags, > */ > memset(&scsi_cmd[1], 0, 5); > =20 > + 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] =3D 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 *sd= ev) > } > } > =20 > + /* > + * 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 t= his for any devices that don't get a driver attached to them?