Re: [PATCH v2 1/2] wifi: ath12k: support calibration-variant from device tree

On 6/30/2026 9:30 PM, Andrew LaMarche wrote:
> ath10k and ath11k support reading calibration variants from the device
> tree to locate the correct Board Description File (BDF). The ath12k-wsi
> binding already describes using qcom,calibration-variant but it is not
> implemented in the driver.
> 
> Many ath12k designs expose all the radios under a single phy, each of
> which typically require a separate BDF. Without this, the radios may not
> come up or will not be calibrated correctly.
> 
> Fix this by parsing the device tree for the generation-agnostic
> qcom,calibration-variant. This allows the driver to properly select,
> read and apply the correct BDF.
> 
> Signed-off-by: Andrew LaMarche <[email protected]>
> ---
> Changes in v2:
> - Drop ath12k-specific binding qcom,ath12k-calibration-variant in favor
>   of generation agnostic qcom,calibration-variant.
> - Link to v1: https://lore.kernel.org/all/[email protected]
> ---
>  drivers/net/wireless/ath/ath12k/core.c | 22 ++++++++++++++++++++++
>  drivers/net/wireless/ath/ath12k/qmi.c  |  4 ++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/core.c b/drivers/net/wireless/ath/ath12k/core.c
> index 742d4fd1b598..52c28864c63c 100644
> --- a/drivers/net/wireless/ath/ath12k/core.c
> +++ b/drivers/net/wireless/ath/ath12k/core.c
> @@ -812,6 +812,28 @@ int ath12k_core_check_smbios(struct ath12k_base *ab)
>  	return 0;
>  }
>  
> +int ath12k_core_check_dt(struct ath12k_base *ab)
> +{
> +	size_t max_len = sizeof(ab->qmi.target.bdf_ext);
> +	const char *variant = NULL;
> +	struct device_node *node;
> +
> +	node = ab->dev->of_node;
> +	if (!node)
> +		return -ENOENT;
> +
> +	of_property_read_string(node, "qcom,calibration-variant",
> +			&variant);
> +	if (!variant)
> +		return -ENODATA;
> +
> +	if (strscpy(ab->qmi.target.bdf_ext, variant, max_len) < 0)
> +		ath12k_dbg(ab, ATH12K_DBG_BOOT,
> +				"bdf variant string is longer than the buffer can accommodate (variant: %s)\n", variant);
> +
> +	return 0;
> +}
> +
>  static int ath12k_core_soc_create(struct ath12k_base *ab)
>  {
>  	int ret;
> diff --git a/drivers/net/wireless/ath/ath12k/qmi.c b/drivers/net/wireless/ath/ath12k/qmi.c
> index fd762b5d7bb5..3cf39ae06fd3 100644
> --- a/drivers/net/wireless/ath/ath12k/qmi.c
> +++ b/drivers/net/wireless/ath/ath12k/qmi.c
> @@ -2945,6 +2945,10 @@ int ath12k_qmi_request_target_cap(struct ath12k_base *ab)
>  	if (r)
>  		ath12k_dbg(ab, ATH12K_DBG_QMI, "SMBIOS bdf variant name not set.\n");
>  
> +	r = ath12k_core_check_dt(ab);

I understand there are already some variant exacting helper (ACPI, SMBIOS) being called
here, but they really should not. After all, how could a qmi message relates to ACPI or
SMBIOS?

I'd like firstly move the existing helpers out and then add the new DT helper.

> +	if (r)> +		ath12k_dbg(ab, ATH12K_DBG_QMI, "DT bdf variant name not set.\n");
> +
>  	r = ath12k_acpi_start(ab);
>  	if (r)
>  		/* ACPI is optional so continue in case of an error */