Re: [PATCH ath-next] wifi: ath12k: Create symlink for each radio in a wiphy

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

On 4/2/2026 1:14 PM, Roopni Devanathan wrote:
> In single-wiphy design, when more than one radio is registered as a
> single-wiphy in the mac80211 layer, the following warnings are seen:
> 
> 1. debugfs: File 'ath12k' in directory 'phy0' already present!
> 2. debugfs: File 'simulate_fw_crash' in directory 'pci-0000:57:00.0' already present!
>    debugfs: File 'device_dp_stats' in directory 'pci-01777777777777777777777:57:00.0' already present!
> 
> When more than one radio is registered as a single-wiphy, symlinks for
> all the radios are created in the same debugfs directory:
> /sys/kernel/debug/ieee80211/phyX/ath12k, resulting in warning 1. When a
> symlink is created for the first radio, since the 'ath12k' directory is
> not present, it will be created and no warning will be thrown. But when
> symlink is created for more than one radio, since the 'ath12k'
> directory was already created for symlink for radio 1, a warning is
> thrown complaining that 'ath12k' directory is already present. To resolve
> warning 1, create symlink for each radio in separate debugfs directories.
> For the first radio, the symlink will always be the 'ath12k' directory.
> This ensures that the existing directory structure is retained for
> single-wiphy and multi-wiphy architectures. In single-wiphy architecture
> with multiple radios, create symlink in separate debugfs directories
> introduced by mac80211.
> 
> Existing debugfs directory in single-wiphy architecture:
> /sys/kernel/debug/ieee80211/phyX/ath12k is a symlink to
> /sys/kernel/debug/ath12k/pci-0001:01:00.0/macY
> 
> Proposed debugfs directory in single-wiphy architecture with one radio:
> /sys/kernel/debug/ieee80211/phyX/ath12k is a symlink to
> /sys/kernel/debug/ath12k/pci-0001:01:00.0/mac0
> 
> Proposed debugfs directory in single-wiphy architecture with more than
> one radio:
> /sys/kernel/debug/ieee80211/phyX/radio0/ath12k is a symlink to
> /sys/kernel/debug/ath12k/pci-0001:01:00.0/mac0 and
> /sys/kernel/debug/ieee80211/phyX/radioY/ath12k is a symlink to
> /sys/kernel/debug/ath12k/pci-0001:01:00.0/macY
> 
> Where X is phy index and Y is radio index, seen in
> 'iw phyX info | grep Idx'. Two symlinks for the first radio are to ensure
> compatibility with the existing design. Add radio_idx inside ar, to track
> the radio index in probing order.
> 
> API ath12k_debugfs_pdev_create() that creates SoC entries is called more
> than once when hardware group starts up, resulting in warning 2. To
> resolve this warning, remove all other calls to this API and add one
> inside the ath12k_core_pdev_create(). This API carries all pdev-specific
> initializations and can conveniently hold a call to
> ath12k_debugfs_pdev_create().
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
> 
> Co-developed-by: Harshitha Prem <harshitha.prem@oss.qualcomm.com>
> Signed-off-by: Harshitha Prem <harshitha.prem@oss.qualcomm.com>
> Signed-off-by: Roopni Devanathan <roopni.devanathan@oss.qualcomm.com>
> ---
>  drivers/net/wireless/ath/ath12k/core.c    |  4 ++--
>  drivers/net/wireless/ath/ath12k/core.h    |  2 ++
>  drivers/net/wireless/ath/ath12k/debugfs.c | 29 +++++++++++++++++++----
>  drivers/net/wireless/ath/ath12k/mac.c     |  2 +-
>  4 files changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/core.c b/drivers/net/wireless/ath/ath12k/core.c
> index c31c47fb5a73..2519e2400d58 100644
> --- a/drivers/net/wireless/ath/ath12k/core.c
> +++ b/drivers/net/wireless/ath/ath12k/core.c
> @@ -835,8 +835,6 @@ static int ath12k_core_soc_create(struct ath12k_base *ab)
>  		goto err_qmi_deinit;
>  	}
>  
> -	ath12k_debugfs_pdev_create(ab);
> -
>  	return 0;
>  
>  err_qmi_deinit:
> @@ -869,6 +867,8 @@ static int ath12k_core_pdev_create(struct ath12k_base *ab)
>  		goto err_dp_pdev_free;
>  	}
>  
> +	ath12k_debugfs_pdev_create(ab);
> +
>  	return 0;
>  
>  err_dp_pdev_free:
> diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
> index 59c193b24764..046249c8763e 100644
> --- a/drivers/net/wireless/ath/ath12k/core.h
> +++ b/drivers/net/wireless/ath/ath12k/core.h
> @@ -588,6 +588,7 @@ struct ath12k_dbg_htt_stats {
>  struct ath12k_debug {
>  	struct dentry *debugfs_pdev;
>  	struct dentry *debugfs_pdev_symlink;
> +	struct dentry *debugfs_pdev_symlink_default;
>  	struct ath12k_dbg_htt_stats htt_stats;
>  	enum wmi_halphy_ctrl_path_stats_id tpc_stats_type;
>  	bool tpc_request;
> @@ -673,6 +674,7 @@ struct ath12k {
>  	u8 pdev_idx;
>  	u8 lmac_id;
>  	u8 hw_link_id;
> +	u8 radio_idx;
>  
>  	struct completion peer_assoc_done;
>  	struct completion peer_delete_done;
> diff --git a/drivers/net/wireless/ath/ath12k/debugfs.c b/drivers/net/wireless/ath/ath12k/debugfs.c
> index 358031fa14eb..8c81a1c22449 100644
> --- a/drivers/net/wireless/ath/ath12k/debugfs.c
> +++ b/drivers/net/wireless/ath/ath12k/debugfs.c
> @@ -1473,18 +1473,35 @@ void ath12k_debugfs_register(struct ath12k *ar)
>  {
>  	struct ath12k_base *ab = ar->ab;
>  	struct ieee80211_hw *hw = ar->ah->hw;
> -	char pdev_name[5];
> +	struct ath12k_hw *ah = ath12k_hw_to_ah(hw);
> +	struct dentry *ath12k_fs;
>  	char buf[100] = {};
> +	char pdev_name[5];
>  
>  	scnprintf(pdev_name, sizeof(pdev_name), "%s%d", "mac", ar->pdev_idx);
>  
>  	ar->debug.debugfs_pdev = debugfs_create_dir(pdev_name, ab->debugfs_soc);
>  
>  	/* Create a symlink under ieee80211/phy* */
> -	scnprintf(buf, sizeof(buf), "../../ath12k/%pd2", ar->debug.debugfs_pdev);
> -	ar->debug.debugfs_pdev_symlink = debugfs_create_symlink("ath12k",
> -								hw->wiphy->debugfsdir,
> -								buf);
> +	if (ar->radio_idx == 0) {
> +		scnprintf(buf, sizeof(buf), "../../ath12k/%pd2",
> +			  ar->debug.debugfs_pdev);
> +		ath12k_fs = hw->wiphy->debugfsdir;
> +
> +		/* symbolic link for compatibility */
> +		ar->debug.debugfs_pdev_symlink_default = debugfs_create_symlink("ath12k",
> +										ath12k_fs,
> +										buf);
> +	}
> +
> +	if (ah->num_radio > 1) {
> +		scnprintf(buf, sizeof(buf), "../../../ath12k/%pd2",
> +			  ar->debug.debugfs_pdev);
> +		ath12k_fs = hw->wiphy->radio_cfg[ar->radio_idx].radio_debugfsdir;
> +		ar->debug.debugfs_pdev_symlink = debugfs_create_symlink("ath12k",
> +									ath12k_fs,
> +									buf);
> +	}
>  
>  	if (ar->mac.sbands[NL80211_BAND_5GHZ].channels) {
>  		debugfs_create_file("dfs_simulate_radar", 0200,
> @@ -1513,7 +1530,9 @@ void ath12k_debugfs_unregister(struct ath12k *ar)
>  
>  	/* Remove symlink under ieee80211/phy* */
>  	debugfs_remove(ar->debug.debugfs_pdev_symlink);
> +	debugfs_remove(ar->debug.debugfs_pdev_symlink_default);
>  	debugfs_remove_recursive(ar->debug.debugfs_pdev);
>  	ar->debug.debugfs_pdev_symlink = NULL;
> +	ar->debug.debugfs_pdev_symlink_default = NULL;
>  	ar->debug.debugfs_pdev = NULL;
>  }
> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
> index 553ec28b6aaa..c2b747f1b9f5 100644
> --- a/drivers/net/wireless/ath/ath12k/mac.c
> +++ b/drivers/net/wireless/ath/ath12k/mac.c
> @@ -15065,6 +15065,7 @@ static struct ath12k_hw *ath12k_mac_hw_allocate(struct ath12k_hw_group *ag,
>  		ar->hw_link_id = pdev->hw_link_id;
>  		ar->pdev = pdev;
>  		ar->pdev_idx = pdev_idx;
> +		ar->radio_idx = i;
>  		pdev->ar = ar;
>  
>  		ag->hw_links[ar->hw_link_id].device_id = ab->device_id;
> @@ -15132,7 +15133,6 @@ int ath12k_mac_allocate(struct ath12k_hw_group *ag)
>  		if (!ab)
>  			continue;
>  
> -		ath12k_debugfs_pdev_create(ab);
>  		ath12k_mac_set_device_defaults(ab);
>  		total_radio += ab->num_radios;
>  	}
> 
> base-commit: 15551ababf6d4e857f2101366a0c3eaa86dd822c

Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>