Hello, Mark. Mark Lord wrote: > Make libata more robust when parsing the multi_count > field from a drive's identify data. This prevents us from > attempting to use dubious multi_count values ad infinitum. > > Reset dev->multi_count to zero and reprobe it each time > through this routine, as it can change on device reset. > > Also ensure that the reported "maximum" value is valid > and is a power of two, and that the reported "count" value > is valid and also a power of two. And that the "count" > value is not greater than the "maximum" value. > > Signed-off-by: Mark Lord <mlord@xxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> The patch looks safe to me although requiring power_of_2 on max seems a bit too strict. For configuration, ata_dev_configure() is the right place. I think the following should work. * add dev->multi_limit which is initialized to -1 on ata_dev_init(). * during ata_dev_configure() if multi_limit < 0, set it to device max. * set dev->multi to rounddown_pow_of_two(multi_limit) and issue SET_MULTI. On EH side, ata_eh_speed_down() is the place to handle it. It can probably piggy back on ATA_EH_SPDN_SPEED_DOWN block. All it has to do is reducing dev->multi_limit. dev_config will run later and apply it. I'm not sure how the speed down strategy should exactly be tho. It is distinguisible from regular transfer errors? Thanks. -- tejun -- 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
