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Date: Mon, 19 Jan 2015 10:24:59 -0600
From: Jeremy White <jwhite@codeweavers.com>
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Subject: Re: [Qemu-devel] [PATCH] Retrieve the correct TD byte when checking
 an ATR.
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To: =?UTF-8?B?TWFyYy1BbmRyw6kgTHVyZWF1?= <marcandre.lureau@gmail.com>
Cc: qemu-devel@nongnu.org

>> The '40' should have been the second TD; instead
>> the FF is used, incorrectly.
> 
> The second TD? There is only one here, T0 = 0x95 & 0xf0 >> 4 = b1001

Yes, sorry, I should not have capitalized TD in my comment.  The code
uses the variable 'td' to hold the upper 4 bits of T0, and then, if
present, the upper 4 bits of TD1.  So what is read imprecisely is the
upper 4 bits of TD1.

I don't know qemu patch protocol; that seems like a very minor detail in
the comment; does it justify a resubmit?

> 
>>
>> Signed-off-by: Jeremy White <jwhite@codeweavers.com>
>> ---
>>  hw/usb/ccid-card-passthru.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/usb/ccid-card-passthru.c b/hw/usb/ccid-card-passthru.c
>> index 10f1d30..2ae3b81 100644
>> --- a/hw/usb/ccid-card-passthru.c
>> +++ b/hw/usb/ccid-card-passthru.c
>> @@ -168,8 +168,8 @@ static int check_atr(PassthruState *card, uint8_t *data, int len)
>>              opt_bytes++;
>>          }
>>          if (td & 0x8) {
>> -            opt_bytes++;
>>              td = data[opt_bytes + 2] >> 4;
>> +            opt_bytes++;
>>          }
>>      }
>>      if (len < 2 + historical_length + opt_bytes) {
>> --
>> 1.7.10.4
>>
>>
> 
> That looks correct, opt_bytes before incrementing points to the current TD.
> 
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>