On Wed, 2006-03-22 at 08:52 -0700, Ju, Seokmann wrote: > On Tuesday, March 21, 2006 6:02 PM, James Bottomley wrote: > > I don't understand the question. Are you asking why > > sd_read_write_protect_flag and sd_read_cache_type operate in the way > > they do? i.e. header first then actual data. > For any SCSI command including MODE_SENSE, 'bufflen'in scsi_cmnd structure holds actual data buffer size in bytes if 'use_sg' flage is NOT set. > The question is that "value of bufflen is 4 for the sd_read_cache_type operation and that is NOT sufficient to return header and page data by driver". > If there is something that I misunderstood with the operation, please guide. If you look at the functions in sd.c you'll see it goes about asking for mode sense very carefully, because there are a lot of broken devices out there. The first request is only for enough of the headers to work out the length of the page. James - : 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
