On Thu, Oct 25 2007 at 15:03 +0200, Alexander Sabourenkov <screwdriver@xxxxxxxxx> wrote: > Hello. > > > Background: > Promise TX4 SATA300 with sata_promise driver generates lots of errors, > both read and write. > > I'm now trying to port Promise-written driver, which works ok with > 2.6.11, to 2.6.22, > so that I can hopefully discover the error-inducing difference between > them, and gain > some understanding of kernel internals in the process. > > I have somewhat cleaned up the horrible mess the Promise driver code > is, so that it compiles, > loads and attaches to the controller. > > > Problem: > > Its internal port scan prints out correct information about hard > drive(s) discovered, and correctly > (i think) fills out response to the INQUIRY command, but when scsi > subsystem receives it back, > it contains some garbage instead. > > The same code works ok on 2.6.11, and I think it would work ok up to > 2.6.16 at least, but I have not checked yet. > > Question: > Can anyone please point out some drastic change in SCSI subsystem > (and what it would take to fix the driver up) > that would result in such behavior, so that I can save some time > digging it up myself? > > Just at the top of my head without looking at the code at all. I would say the bigest change would be the use of use_sg != 0 for all commands in Later kernels. (k>=2.6.17) Look for and around the scsi_cmnd->request_buffer usage. It used to be that for commands like INQUIRY it points to a linear char pointer. Today it will always point to a scatterlist array and use_sg is the sg count of that array. (Usually ==1 in the INQUIRY case) Just a shot in the dark (Where is the code for that driver?) Boaz - 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
