Maciej W. Rozycki wrote:
On Sat, 14 Feb 2009, Mark Lord wrote:
It has the current capacity in words 57-58 swapped:
/dev/sdb:
0c5a 037f 0000 000a 8723 0275 0037 0030
000a 0000 2020 2020 2020 2020 2020 424d
3948 4d31 5020 2020 0003 0040 0004 302e
3336 2020 2020 436f 6e6e 6572 2050 6572
6970 6865 7261 6c73 2032 3430 4d42 202d
2043 5033 3032 3534 2020 2020 2020 8010
0000 0001 0000 0200 0202 0001 037f 000a
0037 0007 82da 0000 0000 0000 0000 0000
It must be 82da 0007, not 0007 82da.
IIRC, the IDE core doesn't trust the value reported in these words
..
That's right. I wrote the IDE code that way
*specifically* due to a (different) Conner drive
I had here at the time.
It happened for some Maxtor drives too. The reason is the ATA-1 spec was
not explicit about how words 57 and 58 were meant to be ordered and some
manufacturers interpreted it one and some the other way. It looks like
libata needs to be fixed.
Here's the relevant code, it appears (drivers/ata/libata-core.c at line
1321):
static u64 ata_id_n_sectors(const u16 *id)
{
if (ata_id_has_lba(id)) {
if (ata_id_has_lba48(id))
return ata_id_u64(id, 100);
else
return ata_id_u32(id, 60);
} else {
if (ata_id_current_chs_valid(id))
return ata_id_u32(id, 57);
else
return id[1] * id[3] * id[6];
}
}
It looks like it's getting into the ata_id_current_chs_valid(id) path,
since all the values that function checks are indeed valid, but the
values in words 57-58 are not. There seems to be no real reason to use
those values since the same can be calculated from the reported CHS, so
you could change that code to:
if (ata_id_current_chs_valid(id))
return id[54] * id[55] * id[56];
else
return id[1] * id[3] * id[6];
Hanno, would you be able to try building a kernel with a modified
drivers/ata/libata-core.c as above (in current -git it would be changing
line 1330) and see if that resolves the problem?
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