Re: [PATCH ath-next v3] wifi: ath12k: advertise interface MAC address pool

[Baochen Qiang <baochen.qiang@oss.qualcomm.com>]

On 9/22/2026 1:30 AM, Vitor Soares wrote:
> From: Vitor Soares <vitor.soares@toradex.com>
> 
> ath12k supports creating vdevs with addresses provided by mac80211.
> Userspace can already make concurrent interfaces work by explicitly
> assigning different locally administered addresses.
> 
> However, ath12k does not advertise an address list, so when a second
> interface is created without an explicit address, mac80211 has nothing
> to pick from and falls back to the permanent address. If the first
> interface is already running with that address, bringing up the second
> one fails with -ENOTUNIQ.
> 
> As in ath11k, provide a list of usable addresses so
> ieee80211_assign_perm_addr() can hand each new interface an unused one.
> Keep the first entry as the wiphy's permanent MAC address. Generate the
> remaining entries as locally administered variants by changing only the
> upper nibble of the first octet, which naturally limits the pool to 16
> unique addresses.
> 
> The cfg80211 definition of wiphy->addresses does not specify where the
> addresses must come from. Some ath12k platforms use it as an interface
> MAC address pool, while others use it for firmware-provided per-radio
> addresses. Gate the generated address pool behind
> advertise_iface_mac_pool and enable it for WCN7850 and QCC2072.
> 
> Other platforms keep the existing behavior.
> 
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3
> 
> Assisted-by: LLM
> Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
> ---
> v3:
> - Rename host_alloc_iface_mac to advertise_iface_mac_pool.
> - Clear wiphy->addresses and wiphy->n_addresses during cleanup.
> - Drop the single-radio check and rely on hw_params gating.
> - Enable the generated interface MAC pool for WCN7850 and QCC2072
>   (QCC2072 compile-tested only).
> - Follow kernel block comment style.
> - Link for v2: https://lore.kernel.org/all/20260915152815.254016-2-ivitro@gmail.com/
> 
> v2:
> - Gate generated interface MAC address list behind hw_params
>   host_alloc_iface_mac, as suggested by Kang Yang.
> - Enable it only for WCN7850, the only part available for testing here.
> - Add Assisted-by: tag.
> - Link for v1: https://lore.kernel.org/all/20260902082219.3010793-2-ivitro@gmail.com/
> ---
>  drivers/net/wireless/ath/ath12k/hw.h       |  1 +
>  drivers/net/wireless/ath/ath12k/mac.c      | 48 ++++++++++++++++++++++
>  drivers/net/wireless/ath/ath12k/wifi7/hw.c |  6 +++
>  3 files changed, 55 insertions(+)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/hw.h b/drivers/net/wireless/ath/ath12k/hw.h
> index e790de5737db..c58db8482aa4 100644
> --- a/drivers/net/wireless/ath/ath12k/hw.h
> +++ b/drivers/net/wireless/ath/ath12k/hw.h
> @@ -238,6 +238,7 @@ struct ath12k_hw_params {
>  	} client;
>  
>  	bool host_alloc_ml_id;
> +	bool advertise_iface_mac_pool;
>  };
>  
>  struct ath12k_hw_ops {
> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
> index d4116ba0da08..46f5f338f44c 100644
> --- a/drivers/net/wireless/ath/ath12k/mac.c
> +++ b/drivers/net/wireless/ath/ath12k/mac.c
> @@ -14743,6 +14743,50 @@ static void ath12k_mac_cleanup_unregister(struct ath12k *ar)
>  	kfree(ar->mac.sbands[NL80211_BAND_6GHZ].channels);
>  }
>  
> +static void ath12k_mac_cleanup_mac_address_list(struct ath12k_hw *ah)
> +{
> +	kfree(ah->hw->wiphy->addresses);
> +	ah->hw->wiphy->addresses = NULL;
> +	ah->hw->wiphy->n_addresses = 0;
> +}
> +
> +static void ath12k_mac_setup_mac_address_list(struct ath12k_hw *ah,
> +					      const u8 *mac_addr)
> +{
> +	struct mac_address *addresses;
> +	struct ath12k *ar;
> +	u16 n_addresses;
> +	int i;
> +
> +	ar = ath12k_ah_to_ar(ah, 0);
> +	if (!ar->ab->hw_params->advertise_iface_mac_pool)
> +		return;

commit message does not describe why only the first radio is checked. From previous
revision I know the purpose is to enable only WCN7850/QCC2072. Better to describe it in
commit message, as well as leaving a comment here.

> +
> +	/*
> +	 * Only the upper nibble of the first octet is varied, so at most 16
> +	 * addresses can be derived from one base.
> +	 */
> +	n_addresses = min_t(u16, TARGET_NUM_VDEVS(ar->ab), 16);
> +	if (n_addresses <= 1)
> +		return;
> +
> +	addresses = kzalloc_objs(*addresses, n_addresses);
> +	if (!addresses)
> +		return;
> +
> +	ether_addr_copy(addresses[0].addr, mac_addr);
> +	for (i = 1; i < n_addresses; i++) {
> +		ether_addr_copy(addresses[i].addr, mac_addr);
> +		/* set Local Administered Address bit */
> +		addresses[i].addr[0] |= 0x2;
> +
> +		addresses[i].addr[0] += i << 4;
> +	}
> +
> +	ah->hw->wiphy->addresses = addresses;
> +	ah->hw->wiphy->n_addresses = n_addresses;
> +}
> +
>  static void ath12k_mac_hw_unregister(struct ath12k_hw *ah)
>  {
>  	struct ieee80211_hw *hw = ah->hw;
> @@ -14762,6 +14806,7 @@ static void ath12k_mac_hw_unregister(struct ath12k_hw *ah)
>  		ath12k_mac_cleanup_unregister(ar);
>  
>  	ath12k_mac_cleanup_iface_combinations(ah);
> +	ath12k_mac_cleanup_mac_address_list(ah);
>  
>  	SET_IEEE80211_DEV(hw, NULL);
>  }
> @@ -14878,6 +14923,7 @@ static int ath12k_mac_hw_register(struct ath12k_hw *ah)
>  	wiphy->available_antennas_tx = antennas_tx;
>  
>  	SET_IEEE80211_PERM_ADDR(hw, mac_addr);
> +	ath12k_mac_setup_mac_address_list(ah, mac_addr);
>  	SET_IEEE80211_DEV(hw, ab->dev);
>  
>  	ret = ath12k_mac_setup_iface_combinations(ah);
> @@ -15120,6 +15166,8 @@ static int ath12k_mac_hw_register(struct ath12k_hw *ah)
>  		ath12k_mac_cleanup_unregister(ar);
>  	}
>  
> +	ath12k_mac_cleanup_mac_address_list(ah);
> +
>  	SET_IEEE80211_DEV(hw, NULL);
>  
>  	return ret;
> diff --git a/drivers/net/wireless/ath/ath12k/wifi7/hw.c b/drivers/net/wireless/ath/ath12k/wifi7/hw.c
> index ae8df80928b0..ad362244ed9b 100644
> --- a/drivers/net/wireless/ath/ath12k/wifi7/hw.c
> +++ b/drivers/net/wireless/ath/ath12k/wifi7/hw.c
> @@ -445,6 +445,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>  		},
>  
>  		.host_alloc_ml_id = true,
> +		.advertise_iface_mac_pool = false,
>  	},
>  	{
>  		.name = "wcn7850 hw2.0",
> @@ -539,6 +540,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>  		},
>  
>  		.host_alloc_ml_id = false,
> +		.advertise_iface_mac_pool = true,
>  	},
>  	{
>  		.name = "qcn9274 hw2.0",
> @@ -629,6 +631,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>  		},
>  
>  		.host_alloc_ml_id = true,
> +		.advertise_iface_mac_pool = false,
>  	},
>  	{
>  		.name = "ipq5332 hw1.0",
> @@ -713,6 +716,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>  		},
>  
>  		.host_alloc_ml_id = true,
> +		.advertise_iface_mac_pool = false,
>  	},
>  	{
>  		.name = "qcc2072 hw1.0",
> @@ -808,6 +812,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>  		},
>  
>  		.host_alloc_ml_id = false,
> +		.advertise_iface_mac_pool = true,
>  	},
>  	{
>  		.name = "ipq5424 hw1.0",
> @@ -895,6 +900,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>  		},
>  
>  		.host_alloc_ml_id = true,
> +		.advertise_iface_mac_pool = false,
>  	},
>  };
>