Subject: Re: [PATCH] powerpc/powernv: Fix BE PE number to opal_pci_eeh_freeze_clear()

From: Gavin Shan <[email-masked]>
Date: Tue, 2 Aug 2016 09:59:16 +1000

On Mon, Aug 01, 2016 at 08:50:58PM +1000, Michael Ellerman wrote:
>Gavin Shan <[email-masked]> writes:
>
>> The PE number (@frozen_pe_no), filled by opal_pci_next_error() is
>> in big-endian format. Frozen PE number in CPU-endian should be passed
>> to opal_pci_eeh_freeze_clear() when clearing the frozen state if the
>> PE is invalid one.
>>
>> This passes CPU-endian PE number to opal_pci_eeh_freeze_clear() and
>> it should be part of commit <0f36db77643b> ("powerpc/eeh: Fix wrong
>> printed PE number").
>
>Which commit added the broken usage?
>
>Looks like 2a485ad7c88d ("powerpc/powernv: Drop PHB operation
>next_error()") ?
>

It is commit 71b540adffd9 ("powerpc/powernv: Don't escalate non-existing frozen PE").
As commit 0f36db77643b was merged to 4.3 kernel and the changes included in this
patch should be part of the commit. It's why I marked this with 4.3+

>> Cc: [email-masked] # v4.3+
>> Suggested-by: Paul Mackerras <[email-masked]>
>> Signed-off-by: Gavin Shan <[email-masked]>
>> ---
>>  arch/powerpc/platforms/powernv/eeh-powernv.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
>> index 86544ea..75363d9 100644
>> --- a/arch/powerpc/platforms/powernv/eeh-powernv.c
>> +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
>> @@ -1538,7 +1538,7 @@ static int pnv_eeh_next_error(struct eeh_pe **pe)
>>  
>>  				/* Try best to clear it */
>>  				opal_pci_eeh_freeze_clear(phb->opal_id,
>> -					frozen_pe_no,
>> +					be64_to_cpu(frozen_pe_no),
>
>Sparse knew about this:
>
>  arch/powerpc/platforms/powernv/eeh-powernv.c:1541:41: warning: incorrect type in argument 2 (different base types)
>  arch/powerpc/platforms/powernv/eeh-powernv.c:1541:41:    expected unsigned long long [unsigned] [usertype] pe_number
>  arch/powerpc/platforms/powernv/eeh-powernv.c:1541:41:    got restricted __be64 [addressable] [usertype] frozen_pe_no
>

Ok, thanks. I never run sparse before and I will learn from you how to run it.

>And finds some other problems in that file:
>
>  arch/powerpc/platforms/powernv/eeh-powernv.c:875:23: warning: constant 0x8000000000000000 is so big it is unsigned long
>  arch/powerpc/platforms/powernv/eeh-powernv.c:1309:21: warning: restricted __be16 degrades to integer
>

Ok. I will fix it with separate patches.

Thanks,
Gavin

>cheers