Patrick and James: There are a couple of problems with the implementation of the use_10_for_rw and use_10_for_ms flags. The easy problem is that use_10_for_rw is implemented twice: once in sd.c:sd_rw_intr and once in scsi_lib.c:scsi_io_completion. The obvious fix is to remove of them. Since scsi_io_completion is more general, it makes sense to leave the code there and remove it from sd.c. The hard problem is that sometimes devices return an ILLEGAL_REQUEST sense key when they shouldn't. I posted an example a week or two ago; what happened was the use_10_for_rw flag got turned off and from then on only 6-byte commands were used (and of course the device failed to recognize them). Clearly we need a mechanism for going the other way: when a 6-byte command gets ILLEGAL_REQUEST sense, turn the use_10_for_xxx flag back on. The difficulty is that this will cause an infinite retry loop if the device doesn't like either form of the command. Is there a standard way to limit the number of retries for these cases in scsi_io_completion? The code pathway involves getting rid of the scsi_cmnd and keeping only the struct request, so I don't know where an appropriate place would be to store the retry counter. Any ideas? Alan Stern - : 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
