On 08/07/2018 11:02 AM, Thomas Schmitt wrote:
[...] DVD drive [...]
Frank Scheiner wrote:
if a specific CDROM drive and
the assumed "compatible" driver don't work together, this results in a
situation like yours
Oh, sorry for my ignorance, as my Ultra 10 has a CDROM drive installed
instead of a DVDROM drive I was mislead to write "CDROM drive" (although
Fred had problems with a DVDROM drive) but that shouldn't make much of a
All DVD capable drives at IDE are supposed to work by the SCSI/MMC protocol
via ATAPI. So there is few chance that the drive itself is not matched by
the kernel's sr driver.
If the drive does not show up as Linux device, i would rather bet on
a driver mismatch with the IDE/ATAPI controller of the machine.
But interestingly the assumed same controller driver works well for
Gregor's and my Ultra 10 and it also works well when Fred uses a CDROM
What could be the reason for that?
Maybe Fred's Ultra 10 is using another revision of the CMD 646 IDE
controller - my Ultra 10 for example uses a CMD 646U - or a DMA mode is
used for the DVDROM drive that is not working correctly with the CMD 646.
I seem to remember to have read about problems with CMD IDE controllers
used in some Sun machines in the past, but cannot find the info now.
But I did find an interesting post on the NetBSD sparc list (), which
gives some background info on different revisions of CMD 646
controllers. So every CMD 646 controller below 646U2 seems to do things
wrong with UltraDMA modes or it only works with very specific drives.
And it could be that the CDROM drives used (by me and later also by
Fred) just support MWDMA or PIO modes that work well with all CMD 646
revisions. That the DVDROM drive works when used from the firmware could
mean that OBP generally does not activate DMA or specifically disables
it for the CMD 646 controller.
UPDATE: I just tested an UltraDMA2 (UDMA/33) capable DVDROM drive in my
Ultra 10 and didn't have any problems. But it also looks like the
controller driver specifically disables UltraDMA modes and only
configures a maximum of MWDMA2:
[ 35.255080] scsi host0: pata_cmd64x
[ 35.300865] hme 0000:01:01.1 enp1s1f1: renamed from eth0
[ 35.369538] scsi host1: pata_cmd64x
[ 35.432494] ata1: PATA max MWDMA2 cmd 0x1fe02c00000 ctl 0x1fe02c00008
bmdma 0x1fe02c00020 irq 14
[ 35.542765] ata2: PATA max MWDMA2 cmd 0x1fe02c00010 ctl 0x1fe02c00018
bmdma 0x1fe02c00028 irq 14
[ 35.653931] pata_cmd64x: active 10 recovery 10 setup 3.
[ 35.653947] pata_cmd64x: active 10 recovery 10 setup 3.
[ 35.855471] ata1.01: both IDENTIFYs aborted, assuming NODEV
[ 35.858949] ata1.00: ATA-5: WDC WD800AB-00CBA0, 03.06A03, max UDMA/100
[ 35.940006] ata1.00: 156301488 sectors, multi 0: LBA
[ 36.003451] pata_cmd64x: active 3 recovery 1 setup 1.
[ 36.003471] pata_cmd64x: active 3 recovery 1 setup 1.
[ 36.009072] ata1.00: configured for MWDMA2
[ 36.061880] scsi 0:0:0:0: Direct-Access ATA WDC WD800AB-00CB
6A03 PQ: 0 ANSI: 5
[ 36.169978] pata_cmd64x: active 10 recovery 10 setup 3.
[ 36.169992] pata_cmd64x: active 10 recovery 10 setup 3.
[ 36.327225] ata2.00: ATAPI: SAMSUNG DVD-ROM SD-616Q, F401, max UDMA/33
[ 36.409059] pata_cmd64x: active 3 recovery 1 setup 1.
[ 36.409075] pata_cmd64x: active 3 recovery 1 setup 1.
[ 36.411667] ata2.00: configured for MWDMA2
[ 36.465435] scsi 1:0:0:0: CD-ROM SAMSUNG DVD-ROM SD-616Q
F401 PQ: 0 ANSI: 5
[ 36.642314] sd 0:0:0:0: [sda] 156301488 512-byte logical blocks:
(80.0 GB/74.5 GiB)
[ 36.745958] sd 0:0:0:0: [sda] Write Protect is off
[ 36.807635] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 36.807957] sd 0:0:0:0: [sda] Write cache: enabled, read cache:
enabled, doesn't support DPO or FUA
[ 36.926295] sr 1:0:0:0: [sr0] scsi3-mmc drive: 16x/48x cd/rw xa/form2
[ 37.023810] cdrom: Uniform CD-ROM driver Revision: 3.20
[ 37.098287] sr 1:0:0:0: Attached scsi CD-ROM sr0
[ 37.250888] sda: sda1 sda2 sda3
[ 37.299576] sd 0:0:0:0: [sda] Attached SCSI disk
Retesting with the CDROM drive shows that it gets also configured to MWDAM2:
[ 36.294580] ata2.00: ATAPI: CRD-8322B, 1.05, max MWDMA2
[ 36.360599] pata_cmd64x: active 3 recovery 1 setup 1.
[ 36.360615] pata_cmd64x: active 3 recovery 1 setup 1.
[ 36.365323] ata2.00: configured for MWDMA2
[ 36.418764] scsi 1:0:0:0: CD-ROM LG CD-ROM CRD-8322B
1.05 PQ: 0 ANSI: 5
[ 36.605717] sr 1:0:0:0: [sr0] scsi3-mmc drive: 32x/32x cd/rw xa/form2
[ 36.702402] cdrom: Uniform CD-ROM driver Revision: 3.20
[ 37.055470] sr 1:0:0:0: Attached scsi CD-ROM sr0
So actually any support for UltraDMA in the DVDROM or CDROM drive does
not seem to make a difference.