Re: [PATCH] wifi: ath11k: clear shared SRNG pointer state on restart

[Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>]

On 5/14/2026 10:22 AM, Kyle Farnung via B4 Relay wrote:
> From: Kyle Farnung <kfarnung@gmail.com>
> 
> LMAC rings reuse the shared rdp/wrp pointer buffers without going
> through the normal SRNG hw-init path that zeros non-LMAC ring
> pointers. After restart, ath11k_hal_srng_clear() can therefore hand
> stale hp/tp state from the previous firmware instance back to the new
> one.
> 
> Clear the shared pointer buffers while keeping the allocations in
> place so restart still avoids reallocating SRNG DMA memory, but starts
> with fresh ring-pointer state.
> 
> Fixes: 32be3ca4cf78b ("wifi: ath11k: HAL SRNG: don't deinitialize and re-initialize again")
> Cc: stable@vger.kernel.org
> Link: https://lore.kernel.org/all/CAOPSVF04q6uvVdq8GTRLHBrVMdpt9=o9wVcFMc6f-yhmSBcZqQ@mail.gmail.com/
> Signed-off-by: Kyle Farnung <kfarnung@gmail.com>
> ---
> This patch is the result of investigating suspend/resume failures on a
> Lenovo ThinkPad P14s Gen 5 AMD with ath11k.
> 
> I originally proposed extending the existing ath11k PM quirk for this
> platform, but after discussion in [1] and bisection the issue appears to
> be a regression introduced by [2]. There is also a parallel report in [3]
> that appears consistent with the same root cause. This patch keeps the
> intended no-reallocation behavior from that change, but clears the
> preserved shared SRNG pointer state so restart begins from a clean state.
> 
> Testing so far has been limited to local suspend/resume cycling on the
> affected system. The issue was originally reproduced on v7.0.4, and the
> patch was also built and tested on top of ath-current with repeated
> suspend/resume cycles on a Lenovo ThinkPad P14s Gen 5 AMD.
> 
> [1] https://lore.kernel.org/all/CAOPSVF04q6uvVdq8GTRLHBrVMdpt9=o9wVcFMc6f-yhmSBcZqQ@mail.gmail.com/
> [2] 32be3ca4cf78b ("wifi: ath11k: HAL SRNG: don't deinitialize and re-initialize again")
> [3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1132343
> ---
>   drivers/net/wireless/ath/ath11k/hal.c | 13 ++++++++++---
>   1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/hal.c b/drivers/net/wireless/ath/ath11k/hal.c
> index e821e5a62c1c0..0c0aeb803018e 100644
> --- a/drivers/net/wireless/ath/ath11k/hal.c
> +++ b/drivers/net/wireless/ath/ath11k/hal.c
> @@ -1387,14 +1387,21 @@ 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 in ath11k_hal_srng_src_hw_init()
> -	 * and ath11k_hal_srng_dst_hw_init().
> +	/* Preserve the shared pointer buffers, but clear the previous
> +	 * firmware instance's hp/tp state before handing them back to FW.
> +	 * LMAC rings reuse this shared memory without going through the
> +	 * normal SRNG hw-init path that zeros non-LMAC ring pointers.
>   	 */
>   	memset(ab->hal.srng_list, 0,
>   	       sizeof(ab->hal.srng_list));
>   	memset(ab->hal.shadow_reg_addr, 0,
>   	       sizeof(ab->hal.shadow_reg_addr));
> +	if (ab->hal.rdp.vaddr)
> +		memset(ab->hal.rdp.vaddr, 0,
> +		       sizeof(*ab->hal.rdp.vaddr) * HAL_SRNG_RING_ID_MAX);
> +	if (ab->hal.wrp.vaddr)
> +		memset(ab->hal.wrp.vaddr, 0,
> +		       sizeof(*ab->hal.wrp.vaddr) * HAL_SRNG_NUM_LMAC_RINGS);
>   	ab->hal.avail_blk_resource = 0;
>   	ab->hal.current_blk_index = 0;
>   	ab->hal.num_shadow_reg_configured = 0;
> 
> ---
> base-commit: 54a5b38e4396530e5b2f12b54d3844e860ab6784
> change-id: 20260513-kfarnung-ath11k-srng-clear-pointer-state-91d8ab07e5e2
> 
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>