UDMA failure with UDMA/100 CF card, pata_pdc2027x, MPC8347

UDMA failure with UDMA/100 CF card, pata_pdc2027x, MPC8347

[Richard Whitlock]

Having a bit of difficulty with the following:

2.6.27-rc1
pata_pdc2027x.ko

MPC8347
Promise pdc20275


The following console output is produced when I try to load pata_pdc2027x.
Each attempt takes several tens of seconds to fail. Loading the module 
takes 2 to 3 minutes.
Once the module has been loaded, mounting SDA1 takes about 20 seconds, 
but can be accessed successfully (albeit slowly)

Having throttled back to PIO4, it seems to work - but does anyone have 
any ideas why the exceptions in all UDMA modes?


pata_pdc2027x 0000:00:0b.0: version 1.0
pata_pdc2027x 0000:00:0b.0: PLL input clock 16485 kHz
scsi0 : pata_pdc2027x
scsi1 : pata_pdc2027x
ata1: PATA max UDMA/133 mmio m16384@0xc0100000 cmd 0xc01017c0 irq 16
ata2: PATA max UDMA/133 mmio m16384@0xc0100000 cmd 0xc01015c0 irq 16
ata1.00: CFA: LEXAR ATA FLASH CARD, 20070228, max UDMA/100
ata1.00: 7831152 sectors, multi 0: LBA
ata1.00: configured for UDMA/100
scsi 0:0:0:0: Direct-Access     ATA      LEXAR ATA FLASH  2007 PQ: 0 ANSI: 5
sd 0:0:0:0: [sda] 7831152 512-byte hardware sectors (4010 MB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't 
support DPO or FUA
sd 0:0:0:0: [sda] 7831152 512-byte hardware sectors (4010 MB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't 
support DPO or FUA
 sda:<3>ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
ata1.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in
         res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for UDMA/100
ata1: EH complete
ata1.00: limiting speed to UDMA/66:PIO4
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
ata1.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in
         res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for UDMA/66
ata1: EH complete
ata1.00: limiting speed to UDMA/33:PIO4
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
ata1.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in
         res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for UDMA/33
ata1: EH complete
ata1.00: limiting speed to PIO4
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
ata1.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in
         res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: soft resetting link
ata1.00: configured for PIO4
ata1: EH complete
 sda1
sd 0:0:0:0: [sda] Attached SCSI removable disk

Re: UDMA failure with UDMA/100 CF card, pata_pdc2027x, MPC8347

[Alan Cox]

> Having throttled back to PIO4, it seems to work - but does anyone have 
> any ideas why the exceptions in all UDMA modes?

Usually with a CFA device it means you are not using a UDMA capable (and
UDMA rated) adapter. Unfortunately while proper ATA cabling and devices
have a negotiation system there isn't a way to discover this particular
situation.

The boot option "libata.dma=3" disables CFA DMA but leaves ATA and ATAPI
DMA enabled for such cases.

Re: UDMA failure with UDMA/100 CF card, pata_pdc2027x, MPC8347

[Richard Whitlock]

>> Having throttled back to PIO4, it seems to work - but does anyone have 
>> any ideas why the exceptions in all UDMA modes?
>>     
>
> Usually with a CFA device it means you are not using a UDMA capable (and
> UDMA rated) adapter. Unfortunately while proper ATA cabling and devices
> have a negotiation system there isn't a way to discover this particular
> situation.
>   
We have a 2.6.20 port which uses arch/ppc (rather than arch/powerpc) 
which works fine on identical hardware, so I think everything is UDMA 
capable.
With our 2.6.20 ppc port, libata configures my lexar 4GB 300x CF card to 
run at UDMA/100 within about 1.5 seconds - since it works so well, I 
never really looked at the mechanics of it.
Any more ideas?

Re: UDMA failure with UDMA/100 CF card, pata_pdc2027x, MPC8347

[Alan Cox]

> With our 2.6.20 ppc port, libata configures my lexar 4GB 300x CF card to 
> run at UDMA/100 within about 1.5 seconds - since it works so well, I 
> never really looked at the mechanics of it.
> Any more ideas?

Not immediately but finding which release it broke and then bisecting
that release if neccessary is going to make it a lot lot easier to figure.