Re: [PATCH v3] wifi: ath11k: HAL SRNG: don't deinitialize and re-initialize again

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

On 7/22/2025 1:31 PM, Muhammad Usama Anjum wrote:
> Don't deinitialize and reinitialize the HAL helpers. The dma memory is
> deallocated and there is high possibility that we'll not be able to get
> the same memory allocated from dma when there is high memory pressure.
> 
> Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03926.13-QCAHSPSWPL_V2_SILICONZ_CE-2.52297.6
> 
> Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
> Cc: stable@vger.kernel.org
> Cc: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
> Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
> ---
> Changes since v1:
> - Cc stable and fix tested on tag
> - Clear essential fields as they may have stale data
> 
> Changes since v2:
> - Add comment and reviewed by tag
> ---
>  drivers/net/wireless/ath/ath11k/core.c |  6 +-----
>  drivers/net/wireless/ath/ath11k/hal.c  | 16 ++++++++++++++++
>  drivers/net/wireless/ath/ath11k/hal.h  |  1 +
>  3 files changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/core.c b/drivers/net/wireless/ath/ath11k/core.c
> index 4488e4cdc5e9e..34b27711ed00f 100644
> --- a/drivers/net/wireless/ath/ath11k/core.c
> +++ b/drivers/net/wireless/ath/ath11k/core.c
> @@ -2213,14 +2213,10 @@ static int ath11k_core_reconfigure_on_crash(struct ath11k_base *ab)
>  	mutex_unlock(&ab->core_lock);
>  
>  	ath11k_dp_free(ab);
> -	ath11k_hal_srng_deinit(ab);
> +	ath11k_hal_srng_clear(ab);
>  
>  	ab->free_vdev_map = (1LL << (ab->num_radios * TARGET_NUM_VDEVS(ab))) - 1;
>  
> -	ret = ath11k_hal_srng_init(ab);
> -	if (ret)
> -		return ret;
> -
>  	clear_bit(ATH11K_FLAG_CRASH_FLUSH, &ab->dev_flags);
>  
>  	ret = ath11k_core_qmi_firmware_ready(ab);
> diff --git a/drivers/net/wireless/ath/ath11k/hal.c b/drivers/net/wireless/ath/ath11k/hal.c
> index b32de563d453a..e8ebf963f195c 100644
> --- a/drivers/net/wireless/ath/ath11k/hal.c
> +++ b/drivers/net/wireless/ath/ath11k/hal.c
> @@ -1359,6 +1359,22 @@ void ath11k_hal_srng_deinit(struct ath11k_base *ab)
>  }
>  EXPORT_SYMBOL(ath11k_hal_srng_deinit);
>  
> +void ath11k_hal_srng_clear(struct ath11k_base *ab)
> +{
> +	/* No need to memset rdp and wrp memory since each individual
> +	 * segment would get cleared ath11k_hal_srng_src_hw_init() and

nit: s/cleared /cleared in/

> +	 * ath11k_hal_srng_dst_hw_init().
> +	 */
> +	memset(ab->hal.srng_list, 0,
> +	       sizeof(ab->hal.srng_list));
> +	memset(ab->hal.shadow_reg_addr, 0,
> +	       sizeof(ab->hal.shadow_reg_addr));
> +	ab->hal.avail_blk_resource = 0;
> +	ab->hal.current_blk_index = 0;
> +	ab->hal.num_shadow_reg_configured = 0;
> +}
> +EXPORT_SYMBOL(ath11k_hal_srng_clear);
> +
>  void ath11k_hal_dump_srng_stats(struct ath11k_base *ab)
>  {
>  	struct hal_srng *srng;
> diff --git a/drivers/net/wireless/ath/ath11k/hal.h b/drivers/net/wireless/ath/ath11k/hal.h
> index 601542410c752..839095af9267e 100644
> --- a/drivers/net/wireless/ath/ath11k/hal.h
> +++ b/drivers/net/wireless/ath/ath11k/hal.h
> @@ -965,6 +965,7 @@ int ath11k_hal_srng_setup(struct ath11k_base *ab, enum hal_ring_type type,
>  			  struct hal_srng_params *params);
>  int ath11k_hal_srng_init(struct ath11k_base *ath11k);
>  void ath11k_hal_srng_deinit(struct ath11k_base *ath11k);
> +void ath11k_hal_srng_clear(struct ath11k_base *ab);
>  void ath11k_hal_dump_srng_stats(struct ath11k_base *ab);
>  void ath11k_hal_srng_get_shadow_config(struct ath11k_base *ab,
>  				       u32 **cfg, u32 *len);