On Sun, Feb 10, 2008 at 09:05:17PM +0200, Boaz Harrosh wrote: > - Lots of drivers still use MAX_COMMAND_SIZE. So I have left > that #define but equate it to BLK_MAX_CDB. The way I see it > and is reflected in the patch below is. > MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB > as per the SCSI standard and is not related > to the implementation. > BLK_MAX_CDB. - The allocated space at the request level > > (*)fixed-length here means commands that their size can be determined > by their opcode and the CDB does not carry a length specifier, like > the VARIABLE_LENGTH_CMD(0x7f) command. This is actually not exactly > true and the SCSI standard also defines extended commands and > vendor specific commands that can be bigger than 16 bytes. The kernel > will support these using the same infrastructure used for VARLEN CDB's. > So in effect MAX_COMMAND_SIZE means the maximum size command > scsi-ml supports without specifying a cmd_len by ULD's A comment like this should be near the declaration of MAX_COMMAND_SIZE > +#define MAX_COMMAND_SIZE 16 > +#if (MAX_COMMAND_SIZE > BLK_MAX_CDB) > +# error MAX_COMMAND_SIZE can not be smaller than BLK_MAX_CDB > +#endif No tabs between the # and the rest of the cpp command, please. Either nothing or a single space as indentation instead. Except for those two small nitpicks this looks very good to me. Nice memory saving aswel. - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
