[PATCH] pata_of_platform: fix no irq handling

[Anton Vorontsov]

On Tue, Aug 12, 2008 at 06:18:42PM +0400, Sergei Shtylyov wrote:
> Anton Vorontsov wrote:
>
>>>>> 1. IDE status read does not work. (But am I understand correctly
>>>>>   that IDE works well if IRQ is unspecified? Then this is hardly
>>>>>   an issue.)
>>>>> 2. IDE interrupt comes when it should not. I'd recommend to use
>>>>>   oscilloscope to find out what is happening there, that is, if
>>>>>   the drive actually deasserts its irq line after status read.
>>>>>   If so, than this could be a PIC problem.
>
>>>>> What is the platform on which you're observing the issue, btw?
>
>>>> Another possibility is that you got the wrong interrupt number
>>>> in the device-tree...
>
>>>> Ben.
>
>>> The platform is the AMCC Sequoia board.  We've built a little adapter to
>>> connect a compact flash card to the processor bus.  I believe the
>>> interrupt selection in the device tree is correct, and I've checked over
>>> the u-boot settings for the IRQ line (active high, level sensitive). 
>
>> IDE IRQs are active-low.
>
>    Only on the PCI and only in the native mode. Natively, the IDE INTRQ  
> signal is active-high, rising edge triggering, as on ISA. You seem to 
> have an invertor somewhere, if it's not a PCI chip...

Ugh. Right you are, as always. I've just looked into mpc8349emitx
schematics, there is indeed an inverter on the irq line.

CF in True IDE mode is active-high, sorry.

-- 
Anton Vorontsov
email: cbouatmailru at gmail.com
irc://irc.freenode.net/bd2