2018-01-31 11:22 GMT+08:00 Martin K. Petersen <martin.petersen@xxxxxxxxxx>: > > Weiping, > >> add user friendly command strings sd_wr_cache to enable/disable >> write&read cache. user can enable both write and read cache by one of >> the following commands: > > I remain unconvinced that introducing redundant option strings is a > benefit. > > These shorthand forms may seem obvious to you, but not to everyone > else. Adding to the murkiness is that fact that write cache must be > *enabled* and read cache *disabled* in the protocol. The fact that the > ??rN and RCD columns below contain inverse values just emphasizes that > point that "0" and "1" are not a particularly good interface either. > > It is also confusing that the existing longhand forms will be printed > when the user subsequently queries the state instead of what they used > to toggle it. > Yes, indeed. > > This, however, is pretty much what I was looking for: > >> Encoding | WCE RCD | Write_cache Read_cache >> -------------------------------------------------------------------- >> write through / w0r1 | 0 0 | off on >> none / w0r0 | 0 1 | off off >> write back / w1r1 | 1 0 | on on >> write back, no read (daft) / w1r0 | 1 1 | on off > > Please drop the w?r? options and submit a patch with this table and a > note about the "temporary" prefix. Put it in > Documentation/scsi/sd-parameters.txt or something to that effect. > It's ok for me. > Bonus points for also documenting the remaining sd sysfs attributes and > their options. I'll try. Thanks > > Thanks! > > -- > Martin K. Petersen Oracle Linux Engineering
