Re: [PATCH ath-next v2] wifi: ath12k: provide MAC address list for single-radio wiphys

[Kang Yang <kang.yang@oss.qualcomm.com>]

On 9/15/2026 11:28 PM, 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 radio's own 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 wiphy->addresses semantics are hardware-specific in ath12k: some


@n_addresses: number of addresses in @addresses.
@addresses: If the device has more than one address, set this pointer to 
a list of addresses (6 bytes each). The first one will be used by 
default for perm_addr. In this case, the mask should be set to 
all-zeroes. In this case it is assumed that the device can handle the 
same number of arbitrary MAC addresses.

The cfg80211 definition of wiphy->addresses does not specify where the 
addresses must come from. As a result, different ath12k platforms have 
historically used it in different ways (interface MAC pool vs. 
firmware-provided per-radio MAC addresses). That's why we suggest gating 
this behavior with a hw capability flag, so existing platform behavior 
remains unchanged.




> platforms use it as an interface MAC address pool, while others use it
> for firmware-provided per-radio addresses. Gate host-generated addresses
> behind host_alloc_iface_mac and enable it for WCN7850.
> 
> Handle only single-radio WCN7850 wiphys. Wiphys with more than one radio
> and other hardware families behave exactly as before.
> 
> 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>
> ---
> 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      | 52 ++++++++++++++++++++++
>   drivers/net/wireless/ath/ath12k/wifi7/hw.c |  6 +++
>   3 files changed, 59 insertions(+)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/hw.h b/drivers/net/wireless/ath/ath12k/hw.h
> index 011bb22e21c7..03cb35071e0b 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 host_alloc_iface_mac;


Please notice that, ath12k only reports address pool, and the allocation 
is done by mac80211, so advertise_iface_mac_pool maybe better.



>   };
>   
>   struct ath12k_hw_ops {
> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
> index d4116ba0da08..45be5b08aa40 100644
> --- a/drivers/net/wireless/ath/ath12k/mac.c
> +++ b/drivers/net/wireless/ath/ath12k/mac.c
> @@ -14743,6 +14743,54 @@ 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);

wiphy->addresses = NULL;

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;
> +
> +	/* The pool is derived from one base address, so it can describe only a
> +	 * single-radio wiphy: with more radios each radio has its own base
> +	 * address, possibly from a different ath12k_base.
> +	 */
> +	if (ah->num_radio != 1)
> +		return;
> +

Delete this num_radio check, please use hw_params check only. We cannot 
make sure other chips won't have one radio products in the future(Maybe 
they already have).


> +	ar = ath12k_ah_to_ar(ah, 0);
> +	if (!ar->ab->hw_params->host_alloc_iface_mac)
> +		return;
> +
> +	/* 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 +14810,7 @@ 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 +14927,7 @@ 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 +15170,8 @@ 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 a20c21807344..8658828ea47d 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,
> +		.host_alloc_iface_mac = false,
>   	},
>   	{
>   		.name = "wcn7850 hw2.0",
> @@ -539,6 +540,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>   		},
>   
>   		.host_alloc_ml_id = false,
> +		.host_alloc_iface_mac = true,
>   	},
>   	{
>   		.name = "qcn9274 hw2.0",
> @@ -629,6 +631,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>   		},
>   
>   		.host_alloc_ml_id = true,
> +		.host_alloc_iface_mac = false,
>   	},
>   	{
>   		.name = "ipq5332 hw1.0",
> @@ -713,6 +716,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>   		},
>   
>   		.host_alloc_ml_id = true,
> +		.host_alloc_iface_mac = false,
>   	},
>   	{
>   		.name = "qcc2072 hw1.0",
> @@ -808,6 +812,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>   		},
>   
>   		.host_alloc_ml_id = false,
> +		.host_alloc_iface_mac = false,
>   	},

For QCC2072, i suggest true. And you can mention in commit message for 
WCN7850/QCC2072.




>   	{
>   		.name = "ipq5424 hw1.0",
> @@ -895,6 +900,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
>   		},
>   
>   		.host_alloc_ml_id = true,
> +		.host_alloc_iface_mac = false,
>   	},
>   };
>