[PATCH ath-next V16 1/2] wifi: ath12k: fix VHT MCS assignment

[Pradeep Kumar Chitrapu]

On 10/1/2025 6:31 PM, Jeff Johnson wrote:
> On 10/1/2025 5:07 PM, Pradeep Kumar Chitrapu wrote:
>> From: Baochen Qiang <baochen.qiang at oss.qualcomm.com>
>>
>> While associating, firmware needs the peer's receive capability
>> to calculate its own VHT transmit MCS. Currently, the host
>> sends this information via mcs->rx_mcs_set field, but firmware
>> actually reads it from mcs->tx_mcs_set field. Thjis mismatch is
> 
> s/Thjis/This/
> 
>> incorrect.
>>
>> This issue has not caused failures so far because most peers
>> advertise identical TX and RX capabilities. Fix this by
>> assigning the value to tx_mcs_set as expected.
>>
>> Additionally, the rate control mask is intended to limit our
>> transmit MCS, so it should also apply to the peer's receive
>> capability. Update the logic accordingly.
>>
>> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1
>>
>> Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
>> Signed-off-by: Baochen Qiang <baochen.qiang at oss.qualcomm.com>
>> Signed-off-by: Pradeep Kumar Chitrapu <quic_pradeepc at quicinc.com>
>> ---
>>   drivers/net/wireless/ath/ath12k/mac.c |  7 +++----
>>   drivers/net/wireless/ath/ath12k/wmi.c | 11 +++++++----
>>   drivers/net/wireless/ath/ath12k/wmi.h |  2 ++
> 
> wmi.c and wmi.h need copyright updates to match current guidance.
> 
>>   3 files changed, 12 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
>> index 1d7b60aa5cb0..0d425a1bc0ab 100644
>> --- a/drivers/net/wireless/ath/ath12k/mac.c
>> +++ b/drivers/net/wireless/ath/ath12k/mac.c
>> @@ -2249,7 +2249,6 @@ static void ath12k_peer_assoc_h_vht(struct ath12k *ar,
>>   	struct cfg80211_chan_def def;
>>   	enum nl80211_band band;
>>   	u16 *vht_mcs_mask;
>> -	u16 tx_mcs_map;
>>   	u8 ampdu_factor;
>>   	u8 max_nss, vht_mcs;
>>   	int i, vht_nss, nss_idx;
>> @@ -2340,10 +2339,10 @@ static void ath12k_peer_assoc_h_vht(struct ath12k *ar,
>>   	arg->peer_nss = min(link_sta->rx_nss, max_nss);
>>   	arg->rx_max_rate = __le16_to_cpu(vht_cap->vht_mcs.rx_highest);
>>   	arg->rx_mcs_set = __le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
>> -	arg->tx_max_rate = __le16_to_cpu(vht_cap->vht_mcs.tx_highest);
>> +	arg->rx_mcs_set = ath12k_peer_assoc_h_vht_limit(arg->rx_mcs_set, vht_mcs_mask);
>>   
>> -	tx_mcs_map = __le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
>> -	arg->tx_mcs_set = ath12k_peer_assoc_h_vht_limit(tx_mcs_map, vht_mcs_mask);
>> +	arg->tx_max_rate = __le16_to_cpu(vht_cap->vht_mcs.tx_highest);
>> +	arg->tx_mcs_set = __le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
>>   
>>   	/* In QCN9274 platform, VHT MCS rate 10 and 11 is enabled by default.
>>   	 * VHT MCS rate 10 and 11 is not supported in 11ac standard.
>> diff --git a/drivers/net/wireless/ath/ath12k/wmi.c b/drivers/net/wireless/ath/ath12k/wmi.c
>> index ff6b3d4ea820..2682d89afd44 100644
>> --- a/drivers/net/wireless/ath/ath12k/wmi.c
>> +++ b/drivers/net/wireless/ath/ath12k/wmi.c
>> @@ -2367,10 +2367,13 @@ int ath12k_wmi_send_peer_assoc_cmd(struct ath12k *ar,
>>   	cmd->peer_bw_rxnss_override |= cpu_to_le32(arg->peer_bw_rxnss_override);
>>   
>>   	if (arg->vht_capable) {
>> -		mcs->rx_max_rate = cpu_to_le32(arg->rx_max_rate);
>> -		mcs->rx_mcs_set = cpu_to_le32(arg->rx_mcs_set);
>> -		mcs->tx_max_rate = cpu_to_le32(arg->tx_max_rate);
>> -		mcs->tx_mcs_set = cpu_to_le32(arg->tx_mcs_set);
>> +		/* Firmware interprets mcs->tx_mcs_set field as peer's
>> +		 * RX capability
>> +		 */
>> +		mcs->rx_max_rate = cpu_to_le32(arg->tx_max_rate);
>> +		mcs->rx_mcs_set = cpu_to_le32(arg->tx_mcs_set);
>> +		mcs->tx_max_rate = cpu_to_le32(arg->rx_max_rate);
>> +		mcs->tx_mcs_set = cpu_to_le32(arg->rx_mcs_set);
>>   	}
>>   
>>   	/* HE Rates */
>> diff --git a/drivers/net/wireless/ath/ath12k/wmi.h b/drivers/net/wireless/ath/ath12k/wmi.h
>> index a8c3190e8ad9..6d9c645e3d5d 100644
>> --- a/drivers/net/wireless/ath/ath12k/wmi.h
>> +++ b/drivers/net/wireless/ath/ath12k/wmi.h
>> @@ -4218,8 +4218,10 @@ struct wmi_unit_test_cmd {
>>   struct ath12k_wmi_vht_rate_set_params {
>>   	__le32 tlv_header;
>>   	__le32 rx_max_rate;
>> +	/* MCS at which the peer can transmit */
>>   	__le32 rx_mcs_set;
>>   	__le32 tx_max_rate;
>> +	/* MCS at which the peer can receive */
>>   	__le32 tx_mcs_set;
>>   	__le32 tx_max_mcs_nss;
>>   } __packed;
> I can apply my two comments when I process this series if there are no other
> changes required.
> 
> /jeff
Thanks for the review Jeff..

I will wait for any further review comments.