pata_sl82c105 is unable to properly handle dma (indeed it try to use mwdma2)

[acrux_it at libero.it]

New pata_sl82c105 is unable to properly handle dma (indeed it try to use 
mwdma2).
Old ide driver instead worked fine.

Tested on IBM 9114-275 where to use it i must boot with dma disabled i.e. with 
libata.dma=0

[...]
pata_sl82c105 0000:00:03.1: enabling device (0144 -> 0145)
scsi1 : pata_sl82c105
scsi2 : pata_sl82c105
ata1: PATA max MWDMA2 cmd 0x1f000 ctl 0x1f010 bmdma 0x1f040 irq 165
ata2: PATA max MWDMA2 cmd 0x1f020 ctl 0x1f030 bmdma 0x1f048 irq 165
ata1.00: ATAPI: IBM     DROM00205, NR38, max UDMA/33
ata1.00: configured for MWDMA2
[...]
scsi 1:0:0:0: CD-ROM            IBM      DROM00205        NR38 PQ: 0 ANSI: 2
sr0: scsi3-mmc drive: 24x/24x cd/rw xa/form2 cdda tray
cdrom: Uniform CD-ROM driver Revision: 3.20
sr 1:0:0:0: Attached scsi generic sg3 type 5
[...]
ata1: lost interrupt (Status 0x50)
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Get configuration: 46 00 00 00 00 00 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA2
ata1: EH complete
sr0: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 
20 00
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
ata1: lost interrupt (Status 0x50)
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Xdread, Read track info: 52 01 00 00 00 01 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:08:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA2
ata1: EH complete
sr0: CDROM (ioctl) error, command: Xdread, Read track info 52 01 00 00 00 01 
00 000
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
ata1: lost interrupt (Status 0x50)
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Get configuration: 46 00 00 00 00 00 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA2
ata1: EH complete
sr0: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 
20 00
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
ata1: lost interrupt (Status 0x50)
ata1.00: limiting speed to MWDMA1:PIO4
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Get configuration: 46 00 00 00 00 00 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA1
ata1: EH complete
sr0: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 
20 00
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
ata1: lost interrupt (Status 0x50)
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Get configuration: 46 00 00 00 00 00 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA1
ata1: EH complete
sr0: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 
20 00
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
ata1: lost interrupt (Status 0x50)
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Get configuration: 46 00 00 00 00 00 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA1
ata1: EH complete
sr0: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 
20 00
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
ata1: lost interrupt (Status 0x50)
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Get configuration: 46 00 00 00 00 00 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA1
ata1: EH complete
sr0: CDROM (ioctl) error, command: Get configuration 46 00 00 00 00 00 00 00 
20 00
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
ata1: lost interrupt (Status 0x50)
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 1:0:0:0: CDB: Get configuration: 46 00 00 00 00 00 00 00 20 00
ata1.00: cmd a0/01:00:00:20:00/00:00:00:00:00/a0 tag 0 dma 16416 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for MWDMA1
ata1: EH complete







cheers,
--nico