IDE from current bk tree, UDMA and two channels...

Quoted 4 lines · Marcin Dalecki

Quoted 4 lines

I'd like to apologize to Ingo, his changes were completely innocent. Problem was triggered by Al's 'block device size cleanups' (currently cset 1.403.160.5 on bkbits).

Quoted 8 lines

Quoted 8 lines

Before this change, my system was using 4KB block size when reading from /dev/hdc1, because of blk_size[][] (which is in 1kB units) of this partition was multiple of 2, and so i_size % 4096 was 0. But after Al's change partition size is read from gendisk, and not from blk_size, and gendisk partition size is in 512 bytes units: and, as you can probably guess, now my partition had i_size % 4096 == 512, and so only 512 byte block size was choosen. And with 512 bytes block size my harddisk refuses to cooperate.

Uh-oh...

Let me see if I got it straight:

a) your disk doesn't work with half-Kb requests
b) you have a partition with odd number of sectors
c) hardsect_size is set to half-Kb
d) old code worked since it rounded size to multiple of kilobyte.

Correct?

Quoted 4 lines

Uh-oh...

Let me see if I got it straight:

Quoted 6 lines

a) your disk doesn't work with half-Kb requests
b) you have a partition with odd number of sectors
c) hardsect_size is set to half-Kb
d) old code worked since it rounded size to multiple of kilobyte.

Correct?

Yes, exactly. Replacing disk is not an option...

Quoted 11 lines

Quoted 11 lines

Uh-oh...

Let me see if I got it straight:

a) your disk doesn't work with half-Kb requests
b) you have a partition with odd number of sectors
c) hardsect_size is set to half-Kb
d) old code worked since it rounded size to multiple of kilobyte.

Quoted 3 lines

Quoted 1 line

Correct?

Yes, exactly. Replacing disk is not an option...

OK. At the very least we need a way for driver to tell what the sector size is. And that can be a problem - AFAICS IDE shares the queue for master and slave and sector size is queue property.