On Tue, Apr 21, 2009 at 03:00:10PM -0700, Dave Hansen wrote: > Here's a patch implementing Al's suggestion. Not quite as trivial as > Matthew's, but even nicer aesthetically. (Description stolen from > Matthew's patch). I have verified that this fixes my issue. I prefer this approach, but I'm equally happy with whichever patch James chooses. > Shifting an unsigned char implicitly casts it to a signed int. This > caused 'lba' to sign-extend and Linux would then try READ CAPACITY 16 > which was not supported by at least one drive. Using the > get_unaligned_be*() helpers keeps us from having to worry about how the > extension might occur. > > Signed-off-by: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> Reviewed-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx> > @@ -1344,12 +1345,8 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, > return -EINVAL; > } > > - sector_size = (buffer[8] << 24) | (buffer[9] << 16) | > - (buffer[10] << 8) | buffer[11]; > - lba = (((u64)buffer[0] << 56) | ((u64)buffer[1] << 48) | > - ((u64)buffer[2] << 40) | ((u64)buffer[3] << 32) | > - ((u64)buffer[4] << 24) | ((u64)buffer[5] << 16) | > - ((u64)buffer[6] << 8) | (u64)buffer[7]); > + sector_size = get_unaligned_be32(&buffer[8]); > + lba = get_unaligned_be64(&buffer[0]); The smallest of quibbles ... you have an excess space after the = ... -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
