Re: [PATCH ath-next v4] wifi: ath12k: avoid dynamic alloc when parsing wmi tb

["Nicolas Escande" <nico.escande@gmail.com>]

On Thu Mar 19, 2026 at 12:08 PM CET, Rameshkumar Sundaram wrote:
>
> Since CONFIG_ATH12K is tristate, a built-in boot can continue past a 
> failed ath12k_init() and still run ath12k_wifi7_init().
>
I genuinely thought the kernel prevented this. I was wrong.

> Please ensure that later initialization path is guarded against 
> allocation failure.
>
I can add a flag like so to be able to check from ath12k_wifi7_init() if the
init finished ok. Something in the lines of

diff --git a/drivers/net/wireless/ath/ath12k/core.c b/drivers/net/wireless/ath/ath12k/core.c
index 6c034071cc6d..742fb33f41ff 100644
--- a/drivers/net/wireless/ath/ath12k/core.c
+++ b/drivers/net/wireless/ath/ath12k/core.c
@@ -34,6 +34,9 @@ module_param_named(ftm_mode, ath12k_ftm_mode, bool, 0444);
 MODULE_PARM_DESC(ftm_mode, "Boots up in factory test mode");
 EXPORT_SYMBOL(ath12k_ftm_mode);
 
+bool ath12k_init_ok = false;
+EXPORT_SYMBOL(ath12k_init_ok);
+
 /* protected with ath12k_hw_group_mutex */
 static struct list_head ath12k_hw_group_list = LIST_HEAD_INIT(ath12k_hw_group_list);
 
@@ -2323,7 +2326,14 @@ struct ath12k_base *ath12k_core_alloc(struct device *dev, size_t priv_size,
 
 static int ath12k_init(void)
 {
-	return ath12k_wmi_alloc();
+	int ret;
+
+	ret = ath12k_wmi_alloc();
+	if (ret)
+		return -ENOMEM;
+
+	ath12k_init_ok = true;
+	return 0;
 }
 
 static void ath12k_exit(void)
diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
index 59c193b24764..f35571b1a541 100644
--- a/drivers/net/wireless/ath/ath12k/core.h
+++ b/drivers/net/wireless/ath/ath12k/core.h
@@ -101,6 +101,8 @@ enum ath12k_crypt_mode {
 	ATH12K_CRYPT_MODE_SW,
 };
 
+extern bool ath12k_init_ok;
+
 static inline enum wme_ac ath12k_tid_to_ac(u32 tid)
 {
 	return (((tid == 0) || (tid == 3)) ? WME_AC_BE :
diff --git a/drivers/net/wireless/ath/ath12k/wifi7/core.c b/drivers/net/wireless/ath/ath12k/wifi7/core.c
index a02c57acf137..542ec10fabf1 100644
--- a/drivers/net/wireless/ath/ath12k/wifi7/core.c
+++ b/drivers/net/wireless/ath/ath12k/wifi7/core.c
@@ -38,6 +38,9 @@ void ath12k_wifi7_arch_deinit(struct ath12k_base *ab)
 
 static int ath12k_wifi7_init(void)
 {
+	if (!ath12k_init_ok)
+		return -ENOTSUPP;
+
 	ahb_err = ath12k_wifi7_ahb_init();
 	if (ahb_err)
 		pr_warn("Failed to initialize ath12k Wi-Fi 7 AHB device: %d\n",


I don't like it much but it is easy enough.
But I don't know if there is a more idiomatic way of doing things

> Or may be have this allocated on first device probe and free it on last 
> device deinit ?

That seems even more involved. It would be easier to go back to the previous
version and simply, alloc it once per ath12k_base

What do you guys think ?