Re: [PATCH] ath9k: fix another source of corrupt frames

[Felix Fietkau <nbd@openwrt.org>]

On 2010-05-04 8:09 PM, Luis R. Rodriguez wrote:
> On Tue, May 4, 2010 at 12:58 AM, Felix Fietkau <nbd@openwrt.org> wrote:
>> Atheros hardware supports receiving frames that span multiple
>> descriptors and buffers. In this case, the rx status of every
>> descriptor except for the last one is invalid and may contain random
>> data. Because the driver does not support this, it needs to drop such
>> frames.
>>
>> Signed-off-by: Felix Fietkau <nbd@openwrt.org>
>> ---
>> --- a/drivers/net/wireless/ath/ath9k/common.c
>> +++ b/drivers/net/wireless/ath/ath9k/common.c
>> @@ -57,13 +57,19 @@ static bool ath9k_rx_accept(struct ath_c
>>         * rs_more indicates chained descriptors which can be used
>>         * to link buffers together for a sort of scatter-gather
>>         * operation.
>> -        *
>> +        * reject the frame, we don't support scatter-gather yet and
>> +        * the frame is probably corrupt anyway
>> +        */
>> +       if (rx_stats->rs_more)
>> +               return false;
> 
> Actually this is required by ath9k_htc, it does process these, but
> ath9k doesn't so this could be done within ath9k itself.
I don't see any place in ath9k_htc that processes rs_more. And even if
it did, processing the rx status of a frame that has more descriptors
chained after it would be wrong, since the rx status is only valid for
the last frame of the descriptor chain.
I think my patch would work fine for ath9k_htc as well.

- Felix