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