Did you read ATA-1 through ATA-7 to understand all the variations?Regardless of all of the geometry returns by the drives and their ATA compliance, the existing code will fail for some drives and return values. For instance, the existing code attempts to "fix up" LBA 48 fails to handle LBA 28. In both cases the "fix up" code appears errant - it doesn't create a complete, valid geometry.
On Tue, 2 Aug 2005, Mark Bellon wrote:
The ATA specification tells large disk drives to return C/H/S data of 16383/16/63 regardless of their actual size (other variations on this return include 15 heads and/or 4092 cylinders). Unfortunately these CHS data confuse the existing IDE code and cause it to report invalid geometries in /proc when the disk runs in LBA mode.
The invalid geometries can cause failures in the partitioning tools; partitioning may be impossible or illogical size limitations occur. This also leads to various forms of human confusion.
I attach a patch that fixes this problem while strongly attempting to not break any existing side effects and await any comments.
mark
Signed-off-by: Mark Bellon <mbellon@xxxxxxxxxx>