Re: [PATCH ath-next] wifi: ath10k: switch to of_get_mac_address

[Jeff Johnson <jeff.johnson@oss.qualcomm.com>]

On 8/8/2025 8:15 PM, Rosen Penev wrote:
> In 9d5804662ce1f9bdde0a14c3c40940acbbf09538 , device_get_mac_address was

see
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes

specifically: If you want to refer to a specific commit, don’t just refer to
the SHA-1 ID of the commit. Please also include the oneline summary of the
commit, to make it easier for reviewers to know what it is about.

So in this case:
9d5804662ce1 ("ath10k: retrieve MAC address from system firmware if provided")

> introduced as a generic way to get MAC addresses from anywhere.
> Unfortunately since then, the landscape has changed and the OF version

when did the landscape change? if using device_get_mac_address() is breaking
folks, it would be nice to know which versions of the kernel have the bad
behavior so that the patch can be backported to any broken LTS kernels.

> is required for NVMEM support. The second problem is that with NVMEM
> it's possible that it loads after ath10k. For that reason, check for
> deferred errors and exit out of probe in such a case.
> 
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
>  drivers/net/wireless/ath/ath10k/core.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
> index 6f78f1752cd6..76747eb0925b 100644
> --- a/drivers/net/wireless/ath/ath10k/core.c
> +++ b/drivers/net/wireless/ath/ath10k/core.c
> @@ -11,6 +11,7 @@
>  #include <linux/module.h>
>  #include <linux/firmware.h>
>  #include <linux/of.h>
> +#include <linux/of_net.h>
>  #include <linux/property.h>
>  #include <linux/dmi.h>
>  #include <linux/ctype.h>
> @@ -3456,7 +3457,9 @@ static int ath10k_core_probe_fw(struct ath10k *ar)
>  		ath10k_debug_print_board_info(ar);
>  	}
>  
> -	device_get_mac_address(ar->dev, ar->mac_addr);
> +	ret = of_get_mac_address(ar->dev->of_node, ar->mac_addr);
> +	if (ret == -EPROBE_DEFER)
> +		goto err_free_firmware_files;

Note a similar proposal for ath11k was deferred since it seems to break x86
attachment when there isn't a device tree node:
https://msgid.link/ec974dc0-962b-f611-7bbb-c07a3872f70f@oss.qualcomm.com

I'd have the same concerns here.
(but I didn't dig into how the fwnode items are set if there isn't a DT)

>  
>  	ret = ath10k_core_init_firmware_features(ar);
>  	if (ret) {