freebsd stable - Apr 2003 - ATA driver not as good in 4.8 as 4.5?

I have a Lite-On 24102B burner on an Epox 7KXA (VIA 686A southbridge) 
together with a few SCSI disks.  I recently upgraded from FreeBSD 4.5
to 4.7 then almost immediately to 4.8.  I've had trouble with the burner
since.

With FreeBSD 4.5, I used "sysctl hw.atamodes=---,---,dma,---" to set
the burner to DMA.  Everything then worked fine.  As far as I know it
was using UDMA33.  That's what the BIOS said it was using anyway.

With FreeBSD 4.8 I use "hw.ata.atapi_dma=1" at boot.  This then tells
me it is using UDMA33.  Unfortunately, I then often get this:

    acd0: READ_BIG - HARDWARE ERROR asc=0x08 ascq=0x03 error=0x00

I think this means a DMA error.  (PS why not say what it is?)

If I use atacontrol to downgrade to WDMA2, it works flawlessly (though
somewhat slower than it does in UDMA33 mode).

So, was 4.5 setting my hardware to WDMA2 when I thought it was doing UDMA33?
Has 4.8 introduced bugs that weren't in 4.5?  Is there another setting
I've
missed?

Cheers,

Stephen.

On Tue, Apr 29, 2003 at 01:06:45AM +1000, Stephen McKay
wrote:
> I have a Lite-On 24102B burner on an Epox 7KXA (VIA 686A southbridge)
> together with a few SCSI disks.  I recently upgraded from FreeBSD 4.5
> to 4.7 then almost immediately to 4.8.  I've had trouble with the
burner
> since.
>
> With FreeBSD 4.5, I used "sysctl hw.atamodes=---,---,dma,---" to
set
> the burner to DMA.  Everything then worked fine.  As far as I know it
> was using UDMA33.  That's what the BIOS said it was using anyway.
>
> With FreeBSD 4.8 I use "hw.ata.atapi_dma=1" at boot.  This then
tells
> me it is using UDMA33.  Unfortunately, I then often get this:
>
>     acd0: READ_BIG - HARDWARE ERROR asc=0x08 ascq=0x03 error=0x00
>
> I think this means a DMA error.  (PS why not say what it is?)
>
> If I use atacontrol to downgrade to WDMA2, it works flawlessly (though
> somewhat slower than it does in UDMA33 mode).
>
> So, was 4.5 setting my hardware to WDMA2 when I thought it was doing
UDMA33?
> Has 4.8 introduced bugs that weren't in 4.5?  Is there another setting
I've
> missed?
New ATA driver have some bugs. This bugs is absent in old ATA driver.
For example: I disabled secondary IDE channel in kernel config (ata1)
and in BIOS setup. New ATA driver in any case allocate IRQ 15 and don't
allow any devices use IRQ 15. Old ATA work properly in this case.

New ATA have some troubles with detect hardware: i can't install
freebsd 4.7 from CD to my old box (P-166). Freebsd 4.4 installed
without problem.

Many people complained about bugs in new ATA, but this bugs don't
fixed long time...

PS: sorry for my english

--
Vladislav V. Zhuk (06267)3-60-03  admin@dru.dn.ua  2:465/197@FidoNet.org