> If those are the only LUs you specificly need I'd suggest you just manually call scsi_add_device from your driver for those instead of listing them in REPORT_LUNS and making them part of the normal LUN scan. Yes, we can do that but not sure what would be advantage of making the LLDs to add these ad-hoc hooks instead of scsi_scan handle it on its own and leaving the LLDs from adding them explicitly? Do you foresee any issues (other than few extra scsi_device instances which may not be useful all scsi devices) with scsi_scan scanning all the LUs (including well known LUs)? Regards, Subhash -----Original Message----- From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi-owner@xxxxxxxxxxxxxxx] On Behalf Of 'Christoph Hellwig' Sent: Saturday, September 13, 2014 11:55 AM To: Subhash Jadavani Cc: 'Christoph Hellwig'; 'Dolev Raviv'; James.Bottomley@xxxxxxxxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; linux-scsi-owner@xxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx; santoshsy@xxxxxxxxx; 'Sujit Reddy Thumma'; 'Martin K. Petersen' Subject: Re: [PATCH V3 01/16] scsi: support well known logical units On Thu, Sep 11, 2014 at 05:41:18PM -0700, Subhash Jadavani wrote: > > UFS device has supports 4 different well known logical units: "REPORT_LUNS" > (address: 01h), "UFS Device" (address: 50h), "RPMB" (address: 44h) and > "BOOT" (address: 30h). > > UFS device's power management needs to be controlled by "POWER CONDITION" > field of SSU (START STOP UNIT) command. But this "power condition" > field will take effect only when its sent to "UFS device" well known > logical unit > (address: 50h) hence we require the scsi_device instance to represent > this logical unit in order for the UFS host driver to send the SSU > command for power management. > > We also require the scsi_device instance for "RPMB" (Replay Protected > Memory > Block) LU so user space process can control this LU. If those are the only LUs you specificly need I'd suggest you just manually call scsi_add_device from your driver for those instead of listing them in REPORT_LUNS and making them part of the normal LUN scan. One advantage of the well known LUNs is that you always know where in the LUN namespace they are :) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
