Messages in this thread | | | Date | Mon, 20 Nov 2006 12:54:32 +0100 (MET) | From | Stefan Roese <> | Subject | Re: [PATCH] serial: Use real irq on UART0 (IRQ = 0) on PPC4xx systems |
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On Monday 20 November 2006 12:42, Alan wrote: > On Mon, 20 Nov 2006 12:00:36 +0100 > > Stefan Roese <ml@stefan-roese.de> wrote: > > This patch fixes a problem seen on multiple 4xx platforms, where > > the UART0 interrupt number is 0. The macro "is_real_interrupt" lead > > on those systems to not use an real interrupt but the timer based > > implementation. > > NAK.
I knew it. ;-)
> Zero means "no interrupt" in the Linux space. If you have a physical IRQ > 0 remap it to a convenient number (eg map IRQ's + 1, or stick it on the > end). The logical and physical IRQ numbering in Linux don't have to match > up - and given some platforms have IRQ numbering per bus and the like > clearly doesn't in many cases.
Let's see, if I got this right. You mean that on such a platform, where 0 is a valid physical IRQ, we should assign another value as virtual IRQ number (not 0 and not -1 of course). And then the platform "pic" implementation should take care of the remapping of these virtual IRQ numbers to the physical numbers.
Correct?
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