Subject: Re: [PATCH] pata_of_platform: fix no irq handling

From: Sergei Shtylyov <[email-masked]>
Date: Tue, 12 Aug 2008 18:18:42 +0400

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...

WBR, Sergei