Pata sch

Intel SCH IDE

Hardware Support

Intel US15X, US15W, US15L, UL11L chipsets IDE controller

Modes Supported

PIO, MWDMA, UDMA

Limitations

None

Known Problems

The PATA_SCH driver has problems detecting 40 wire cable and hence the correct UDMA mode on some systems. Specifically we see the following ATA error messages in the dmesg log when IDE hard drive and CD-ROM are present on the cable:

[    4.278671] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6
[    4.278769] ata1.00: BMDMA stat 0x64
[    4.278856] ata1.00: failed command: READ DMA
[    4.278950] ata1.00: cmd c8/00:20:70:ca:ab/00:00:00:00:00/e0 tag 0 dma 16384 in
[    4.278953]          res 51/84:00:8f:ca:ab/00:00:00:00:00/e0 Emask 0x10 (ATA bus error)
[    4.279238] ata1.00: status: { DRDY ERR }
[    4.279322] ata1.00: error: { ICRC ABRT }
[    4.279429] ata1: soft resetting link
[    4.656816] ata1.00: configured for UDMA/100
[    4.688263] ata1.01: configured for UDMA/33
[    4.689038] ata1: EH complete
[    4.703657] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6
[    4.703749] ata1.00: BMDMA stat 0x64
[    4.703834] ata1.00: failed command: READ DMA
[    4.703928] ata1.00: cmd c8/00:20:70:ca:ab/00:00:00:00:00/e0 tag 0 dma 16384 in
[    4.703931]          res 51/84:00:8f:ca:ab/00:00:00:00:00/e0 Emask 0x10 (ATA bus error)
[    4.704163] ata1.00: status: { DRDY ERR }
[    4.704249] ata1.00: error: { ICRC ABRT }
[    4.704355] ata1: soft resetting link
[    5.081245] ata1.00: configured for UDMA/100
[    5.112262] ata1.01: configured for UDMA/33
[    5.113026] ata1: EH complete

One work around to get rid of these messages is to pass the following kernel boot parameters:

libata.force=40c

but surely it would be nice if Linux can handle this situation more gracefully.

For more details please see the [thread] on linux-ide mailing list.

Module Options

None