ATAng no PIO fallback?

[Anish Mistry]

On Thursday 28 August 2003 02:24 am, you wrote:
> It seems Anish Mistry wrote:
> -- Start of PGP signed section.
> > 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 ?
> 
Because the drive does support DMA.  I've tested to see it DMA actually works 
in windows, PIO vs DMA while playing a DVD, and there is a big difference, 
and I can only assume that it works.
> -Søren
> 
> 

-- 
Anish Mistry
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