Problem with mini-PCI-E slot on P2020RDB

Kushwaha Prabhakar-B32579 B32579 at
Fri Apr 8 13:53:57 EST 2011

> -----Original Message-----
> From: Leon Woestenberg [mailto:leon.woestenberg at]
> Sent: Thursday, April 07, 2011 10:50 PM
> To: linuxppc-dev at
> Cc: Kumar Gala; Mahajan Vivek-B08308; Aggrwal Poonam-B10812; Felix
> Radensky; Kushwaha Prabhakar-B32579
> Subject: Re: Problem with mini-PCI-E slot on P2020RDB
> Hello,
> On Thu, Dec 17, 2009 at 9:28 PM, Felix Radensky <felix at>
> wrote:
> > Kumar Gala wrote:
> >> On Dec 17, 2009, at 2:59 AM, Mahajan Vivek-B08308 wrote:
> >>>> Thanks a lot. If I understand you correctly, the only way I can get
> >>>> ath9k driver to work on this board using legacy interrupts is to
> >>>> wait for a hardware fix. Right ?
> >>>>
> >>> Correct
> >>
> >> I'm confused.  What's the issue with IRQ0 on the P2020RDB?  Is it
> >> used for another purpose?
> >
> > There's a problem with IRQ0 with respect to mini-PCI-E slot. I have
> > Atheros wireless card plugged into it. ath9k wireless driver for this
> > card uses legacy PCI-E interrupts, and I get "irq 16: nobody cared"
> > message when driver executes request_irq(). Vivek has come to a
> > conclusion that the problem is related to incorrect IRQ0 routing for
> > mini-PCI-E slot on P2020RDB.
> >
> I would like to understand this issue better, as I seem to be running
> into something similar, and it puts my board design on hold.
> Can someone (from Freescale) explain what happens if a PCI Express end
> point on the mini-PCIe slot raises a legacy interrupt, and where this
> goes wrong?
> From what document or source code file can I conclude that the PCIe
> legacy interrupt is shared with IRQ0?
> I found this:
> P1020E/P2020E RDB System Errata, Last Update: 2/15/2010:
> Problem:IRQ0 held low
> Fix: Add 4.7K pull-up (to 3.3.V) for RTC_INT_N.
> See R420 in Rev D schematic.
> Add 4.7K pull-up (to 3.3.V) for MCU_INT_N.
> See R423 in Rev D schematic.

Hello Leon,

 Yes you are right, PCIe leagacy interrupt is shared with IRQ0. For Atheros issue. 
 Can you please try followings, Meanwhile I will try to dig into it.

Regarding sata_sil24, Please see my e-mail on Linux-ide for correct IDSEL value. 
Please first try IDSEL value mentioned in email on Linux-ide. Then try this URL..


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