Hi Bart, +AD4- -----Original Message----- +AD4- From: Bart Van Assche +AD4- Sent: Friday, August 10, 2018 2:51 AM +AD4- To: hch+AEA-lst.de+ADs- Avri Altman +ADs- linux-scsi+AEA-vger.kernel.org+ADs- hare+AEA-suse.com+ADs- jthumshirn+AEA-suse.de+ADs- martin.petersen+AEA-oracle.com+ADs- +AD4- jejb+AEA-linux.vnet.ibm.com +AD4- Cc: Vinayak Holikatti +ADs- Avi Shchislowski +ADs- Alex Lemberg +ADs- Stanislav Nijnikov +ADs- subhashj+AEA-codeaurora.org +AD4- Subject: Re: +AFs-PATCH v2 1/8+AF0- scsi: Add ufs transport class +AD4- +AD4- On Thu, 2018-08-09 at 23:32 +-0000, Avri Altman wrote: +AD4- +AD4- And as I said before, we think that maintaining the flexibility to have more-than-one +AD4- +AD4- bsg device nodes, will be useful serving as a testing and validation environment. +AD4- +AD4- That is a very vague statement. Please clarify. +AD4- +AD4- +AD4- +AD4APg- +ACI-... +AD4- +AD4- +AD4APg- In addition to the basic SCSI core objects this transport class +AD4- +AD4- +AD4APg- introduces two additional (currently empty) class objects: +AD4- +AD4- +AD4APg- +IBw-ufs-host+IB0- and +IBw-ufs-port+IB0-. There is only one +IBw-ufs-host+IB0- in the +AD4- +AD4- +AD4APg- system, but can be more-than-one +IBw-ufs-ports+IB0-. +AD4- +AD4- +AD4APg- +AD4- +AD4- +AD4APg- ...+ACI- +AD4- +AD4- +AD4- +AD4- +AD4-Since both the ufs-host and ufs-port objects are empty, can both be left out? +AD4- +AD4- But mustn't I declare those classes for the various components of the scsi transport to work? +AD4- +AD4- Are you perhaps referring to the transport+AF8-class+AF8-register() calls in SCSI +AD4- transport drivers? From what I see in existing SCSI transport drivers the +AD4- transport+AF8-class+AF8-register() function is used to register link, port, host, +AD4- vport, rport and other objects. I don't think that a SCSI transport driver +AD4- is required to register host and port objects. +AD4- +AD4- Maybe we should take a step back and discuss first why the new bsg queues +AD4- are registered by a transport driver? Since in case of UFS as far as I can +AD4- see there is no real need to introduce a transport driver other than for +AD4- creating the bsg device nodes, have you considered to add the code for +AD4- creating bsg device nodes to the UFS driver instead of in a UFS transport +AD4- driver? I think transport drivers were introduced as a way to share code +AD4- between multiple SCSI LLDs that use the same transport mechanism. In the +AD4- case of UFS there is only one SCSI LLD. Hence I'm wondering whether we +AD4- really need an UFS transport driver. +AD4- At the moment, the SCSI transport related code could be found at driver/scsi/scsi+AF8-transport+AF8AKg- files. What is a point of hiding the UFS transport code inside the UFS driver? Regards. Stanislav
