ATAng no PIO fallback?
Soren Schmidt
sos at spider.deepcore.dk
Wed Aug 27 23:24:16 PDT 2003
It seems Anish Mistry wrote:
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> On Tuesday 26 August 2003 10:27 pm, Anish Mistry wrote:
> > After removing atapicam from my kernel, so no panics on boot I decided to
> see
> > it DMA was fixed for my CD/DVD combo drive. I changed the
> > hw.ata.atapi_dma="0"
> > to hw.ata.atapi_dma="1" in my /boot/loader.conf. After a reboot I tried to
> > access my cdrom drive, and got the following error messages, which is very
> > similar to the messages when trying to dma before ATAng:
> > Aug 26 22:09:34 littleguy kernel: acd0: WARNING - READ_CD recovered from
> > missing interrupt
> > Aug 26 22:09:34 littleguy kernel: acd0: WARNING - READ_CD UDMA ICRC error
> > (retrying request)
> >
> > The problem is that before with DMA enabled it would try dma a few times
> fail,
> > and then fall back to PIO, whcih though annoying still left the drive in a
> > useable condition. Where as now the drive just stays stuck and unusable.
> >
> > .....
> Anyone thinking about looking into this? I'll just submit a PR, in a day or 2
> if there is no resposne.
> Thanks,
There is no PIO fallback in ATAng (so far), if you know that your ATAPI device
doesn't do DMA why on earth do you enable it ?
-Søren
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