Problem with mini-PCI-E slot on P2020RDB

Felix Radensky felix at
Fri Apr 15 17:20:12 EST 2011

Hi Poonam,

Thanks for the confirmation.


On 04/15/2011 09:27 AM, Kushwaha Prabhakar-B32579 wrote:
> Added Linxppc-dev
>> -----Original Message-----
>> From: Aggrwal Poonam-B10812
>> Sent: Friday, April 15, 2011 11:47 AM
>> To: Felix Radensky
>> Cc: Kushwaha Prabhakar-B32579; leon.woestenberg at
>> Subject: FW: Problem with mini-PCI-E slot on P2020RDB
>> Hello Felix
>> We checked with the Board designer, we need the board fixes "mentioned in
>> Board errata doc" on the board for this issue. Sorry for the confusion.
>> The fixes are not present on RevC, also on some RevDs this fix also may
>> be absent.
>> Please let us know in case of any issues.
>> Regards
>> Poonam
>>> -----Original Message-----
>>> From: Leon Woestenberg [mailto:leon.woestenberg at]
>>> Sent: Wednesday, April 13, 2011 2:52 PM
>>> To: Felix Radensky
>>> Cc: Aggrwal Poonam-B10812; linuxppc-dev at; Gupta
>>> Maneesh-B18878; Kushwaha Prabhakar-B32579
>>> Subject: Re: Problem with mini-PCI-E slot on P2020RDB
>>> Felix,
>>> On Tue, Apr 12, 2011 at 6:54 AM, Felix Radensky
>>> <felix at>
>>> wrote:
>>>> On 04/12/2011 07:05 AM, Aggrwal Poonam-B10812 wrote:
>>>>> As such there is no hardware fix related to this issue between RevC
>>>>> to RevD. The solution was a software patch to resolve the issue
>>>>> related to IRQ0.
>>>> Are you sure ? Please take a look at Freescale document titled
>>>> "P1020E/P2020E RDB System Errata".
>>>> There's errata CE10, IRQ0 held low. It is fixed in Rev D. Vivek
>>>> Mahajan, who looked at the issue back in 2009, estimated that
>>>> problem can be related to missing pull-up on IRQ0.
>>>> This is exactly what is
>>>> fixed in Rev D.
>>> That's my understanding as well.
>>> Check if R420 and R423 are populated. These are the required pull-ups.
>>> On Rev D they are populated. You might be able to add them yourself.
>>> Even if you have an Rev A-C PCB, this fix can already be applied; it
>>> was on my board! (the bottom of the board mentions the schematic
>>> revision)
>>> The resistors have a silkscreen designator block called X, the
>>> resistors are situated to the left and bottom of the silkscreen X.
>>> IIRC, between the flash and Px020 part.
>>> On the left side of R420 (or R423) I measured the block wave from the
>>> RTC, which fires the 32kHz interrupt rate on IRQ0. This fixed by the
>>> u- boot patch.
>>> Regards,
>>> Leon.

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