Hello, Atsushi. Atsushi Nemoto wrote: > I have a question on CHS calculation in ata_tf_read_block(). > > The calculation in ata_tf_read_block() is: > block = (cyl * dev->heads + head) * dev->sectors + sect; > > but ata_build_rw_tf() does: > track = (u32)block / dev->sectors; > cyl = track / dev->heads; > head = track % dev->heads; > sect = (u32)block % dev->sectors + 1; > > It seems inconsistent. The correct calculation is: > block = (cyl * dev->heads + head) * dev->sectors + sect - 1; > isn't it? Yes, indeed. > I don't have any real problem. Just noticed by code reading. ata_tf_read_block() currently is used only when reporting failed block address to upper layer so off-by-one bug there wouldn't be too visible, especially for the venerable CHS addressing. Care to submit a patch w/ warning message and capping for sect == 0 case? 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
