Hi Bart, +AD4- -----Original Message----- +AD4- From: Bart Van Assche +AD4- Sent: Tuesday, August 21, 2018 4:54 AM +AD4- To: jthumshirn+AEA-suse.de+ADs- hch+AEA-lst.de+ADs- Avri Altman +ADs- +AD4- martin.petersen+AEA-oracle.com+ADs- linux-scsi+AEA-vger.kernel.org+ADs- hare+AEA-suse.com+ADs- +AD4- jejb+AEA-linux.vnet.ibm.com+ADs- Stanislav Nijnikov +AD4- Cc: Vinayak Holikatti +ADs- Avi Shchislowski +ADs- Alex Lemberg +ADs- +AD4- subhashj+AEA-codeaurora.org +AD4- Subject: Re: +AFs-PATCH v2 1/8+AF0- scsi: Add ufs transport class +AD4- +AD4- On Tue, 2018-08-14 at 11:42 +-0000, Stanislav Nijnikov wrote: +AD4- +AD4- From: Bart Van Assche +AD4- +AD4- +AD4- Are you perhaps referring to the transport+AF8-class+AF8-register() calls in SCSI +AD4- +AD4- +AD4- transport drivers? From what I see in existing SCSI transport drivers the +AD4- +AD4- +AD4- transport+AF8-class+AF8-register() function is used to register link, port, host, +AD4- +AD4- +AD4- vport, rport and other objects. I don't think that a SCSI transport driver +AD4- +AD4- +AD4- is required to register host and port objects. +AD4- +AD4- +AD4- +AD4- +AD4- +AD4- Maybe we should take a step back and discuss first why the new bsg +AD4- queues +AD4- +AD4- +AD4- are registered by a transport driver? Since in case of UFS as far as I can +AD4- +AD4- +AD4- see there is no real need to introduce a transport driver other than for +AD4- +AD4- +AD4- creating the bsg device nodes, have you considered to add the code for +AD4- +AD4- +AD4- creating bsg device nodes to the UFS driver instead of in a UFS transport +AD4- +AD4- +AD4- driver? I think transport drivers were introduced as a way to share code +AD4- +AD4- +AD4- between multiple SCSI LLDs that use the same transport mechanism. In +AD4- the +AD4- +AD4- +AD4- case of UFS there is only one SCSI LLD. Hence I'm wondering whether we +AD4- +AD4- +AD4- really need an UFS transport driver. +AD4- +AD4- +AD4- +AD4- At the moment, the SCSI transport related code could be found at +AD4- driver/scsi/scsi+AF8-transport+AF8AKg- files. +AD4- +AD4- What is a point of hiding the UFS transport code inside the UFS driver? +AD4- +AD4- Have you tried to implement the approach I proposed? If so, did you +AD4- encounter +AD4- any issues that made it impossible to implement that approach? If you have +AD4- not yet tried to implement the above proposal, what are you waiting for? Your proposal makes a perfect sense, and it is certainly a feasible path. I also accept your point and withdraw from my intension to create multiple bsg dev nodes. It is just that I couldn't find any other lld that creates its own bsg queue - Currently this is only done within scsi transport and scsi sysfs. So before sending a new RFC, I was hoping to get additional support for your proposal. Will send it in the coming days. Thanks a lot, Avri
