[patch] only update dcache after write succeeds

[Michael Snyder]

Marc Khouzam wrote:
>  
> 
>> -----Original Message-----
>> From: Michael Snyder [mailto:msnyder@vmware.com] 
>> Sent: Monday, September 14, 2009 3:27 PM
>> To: Doug Evans
>> Cc: gdb-patches@sourceware.org; Marc Khouzam; Greg Law; Pedro 
>> Alves; Hui Zhu
>> Subject: Re: [patch] only update dcache after write succeeds
>>
>> Doug Evans wrote:
>>> Hi.
>>>
>>> Marc, Greg: Can you see if this patch fixes things for you?
>> Hey Doug,
>>
>> I tested this change, and it does indeed seem to fix the problem
>> with target record -- but.   ;-)
>>
>> Part of the reason that it works is that record_xfer_partial
>> calls error() instead of returning -1.  If I change it so that
>> it returns -1, things get more complicated.
> 
> Just a note that PRecord used to return -1 which caused memory
> to be changed even when the query was answered with 'n'.
> That is why Hui changed it to error()

OK -- and now I see why it used to change the memory anyway.
The caller (memory_xfer_partial) would call the target beneath.

Makes me suspect that Doug's change is OK in general.