Re: How to fall back to PIO for IDE CD's?

[Martin Husemann <martin%duskware.de@localhost>]

On Wed, Nov 18, 2020 at 10:09:10AM +0100, Julian Coleman wrote:
> I see the same on the V240.  If I try to read a DVD with mplayer on the
> V240 or SPARCle in -9, I'll see "error reading" messages and it will fall
> back to DMA then PIO and work.  In current, I just see the error messages
> and can't read the DVD at all.

It seems to depend on the medium and readability.

I can read a DVD+R just fine, but a real data CD (not CDR) fails with:

aceride0:1:0: lost interrupt
[ 159419.4040795]       type: atapi tc_bcount: 2048 tc_skip: 0
aceride0:1:0: bus-master DMA error: missing interrupt, status=0x21
[ 159419.4040795] aceride0:1:0: device timeout, c_bcount=2048, c_skip=0
[ 159439.7142893] cd0(aceride0:1:0):  Check Condition on CDB: 0x28 00 00 00 00 66 00 00 01 00
[ 159439.7142893]     SENSE KEY:  Media Error
[ 159439.7142893]    INFO FIELD:  102
[ 159439.7142893]      ASC/ASCQ:  CIRC Unrecovered Error
[ 159439.7142893] cd0c: error reading fsbn 408 of 408-411 (cd0 bn 408; cn 4 tn 0 sn 8)


and a commercial (movie) DVD

fails similarily:

aceride0:1:0: lost interrupt
[ 159643.7064013]       type: atapi tc_bcount: 32 tc_skip: 0
aceride0:1:0: bus-master DMA error: missing interrupt, status=0x21
[ 159643.7064013] aceride0:1:0: device timeout, c_bcount=32, c_skip=0
[ 159643.7064013] cd0(aceride0:1:0): generic HBA error


Sounds more like bugs in the aceride driver to me (or missing workarounds for
chip bugs), and that is where I would put hacks like "do not use dma for CD
like drives" too.

Martin