[PATCH v2] wifi: ath12k: fix mac id extraction when MSDU spillover in rx error path

[Nithyanantham Paramasivam]

On 4/11/2024 3:03 PM, Kalle Valo wrote:
> Nithyanantham P <quic_nithp at quicinc.com> writes:
> 
>> From: Karthikeyan Periyasamy <quic_periyasa at quicinc.com>
>>
>> Currently, in the rx error data path, mac id is extracted from the
>> last 64bits of MSDU end description tag for each entry received in
>> the WBM error ring. Then, each entry will be updated into the MSDU
>> list for further processing. The extracted mac id is valid when a
>> single MSDU is not fragmented and received in the WBM error ring.
>>
>> In scenarios where the size of a single MSDU received exceeds the
>> descriptor buffer size, resulting in fragmented or spillover MSDU
>> entries into the WBM error ring. In this case, the extracted mac id
>> from each spillover entry is invalid except the last spillover entry
>> of the MSDU. This invalid mac id leads to packet rejection.
>>
>> To address this issue, check if the MSDU continuation flag is set,
>> then extract the valid mac id from the last spillover entry.
>> Propagate the valid mac id to all the spillover entries of the single
>> MSDU in the temporary MSDU list(scatter_msdu_list). Then, update this
>> into the MSDU list (msdu_list) for further processing.
>>
>> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1
>>
>> Signed-off-by: Karthikeyan Periyasamy <quic_periyasa at quicinc.com>
>> Signed-off-by: Nithyanantham P <quic_nithp at quicinc.com>
> 
> [...]
> 
>> @@ -3807,16 +3816,50 @@ int ath12k_dp_rx_process_wbm_err(struct ath12k_base *ab,
>>   			continue;
>>   		}
>>   
>> +		msdu_data = (struct hal_rx_desc *)msdu->data;
>>   		rxcb->err_rel_src = err_info.err_rel_src;
>>   		rxcb->err_code = err_info.err_code;
>> -		rxcb->rx_desc = (struct hal_rx_desc *)msdu->data;
>> -
>> -		__skb_queue_tail(&msdu_list, msdu);
>> -
>>   		rxcb->is_first_msdu = err_info.first_msdu;
>>   		rxcb->is_last_msdu = err_info.last_msdu;
>>   		rxcb->is_continuation = err_info.continuation;
>> +		rxcb->rx_desc = msdu_data;
>> +
>> +		if (err_info.continuation) {
>> +			__skb_queue_tail(&scatter_msdu_list, msdu);
>> +		} else {
>> +			mac_id = ath12k_dp_rx_get_msdu_src_link(ab,
>> +								msdu_data);
>> +			if (mac_id >= MAX_RADIOS) {
>> +				dev_kfree_skb_any(msdu);
>> +
>> +				/* In any case continuation bit is set
>> +				 * in the previous record, cleanup scatter_msdu_list
>> +				 */
>> +				ath12k_dp_clean_up_skb_list(&scatter_msdu_list);
>> +				continue;
>> +			}
>> +
>> +			if (!skb_queue_empty(&scatter_msdu_list)) {
>> +				struct sk_buff *msdu;
>> +
>> +				skb_queue_walk(&scatter_msdu_list, msdu) {
>> +					rxcb = ATH12K_SKB_RXCB(msdu);
>> +					rxcb->mac_id = mac_id;
>> +				}
>> +
>> +				skb_queue_splice_tail_init(&scatter_msdu_list,
>> +							   &msdu_list);
>> +			}
>> +
>> +			rxcb = ATH12K_SKB_RXCB(msdu);
>> +			rxcb->mac_id = mac_id;
>> +			__skb_queue_tail(&msdu_list, msdu);
>> +		}
>>   	}
> 
> The else branch can be avoided with continue. I did that in the pending
> branch, please check my changes:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?h=pending&id=6c677d91adad4817e7f6ef65a85331f52f0237ee
> 
LGTM.