Re: [PATCH] Revert "wifi: ath12k: Enable REO queue lookup table feature on QCN9274 hw2.0"

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

On 12/8/2025 2:31 AM, Oliver Sedlbauer wrote:
> This reverts commit 3b5e5185881edf4ee5a1af575e3aedac4a38a764.
> 
> The REO queue lookup table feature was enabled in 6.12.y due to an
> upstream backport, but it causes severe RX performance degradation on
> QCN9274 hw2.0 devices.
> 
> With this feature enabled, the vast majority of received packets are
> dropped, reducing throughput drastically and making the device nearly
> unusable.
> 
> Reverting this change restores full RX performance.
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.5-01651-QCAHKSWPL_SILICONZ-1
> 
> Fixes: 3b5e5185881e ("wifi: ath12k: Enable REO queue lookup table feature on QCN9274 hw2.0")
> Signed-off-by: Oliver Sedlbauer <os@dev.tdt.de>
> ---
> Note:
> This commit reverts a backport that was not a fix. The backported change
> breaks previously working behavior on QCN9274 hw2.0 devices and should
> not have been applied to the 6.12.y stable kernel.
> 
>  drivers/net/wireless/ath/ath12k/hw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/hw.c b/drivers/net/wireless/ath/ath12k/hw.c
> index 057ef2d282b2..e3eb22bb9e1c 100644
> --- a/drivers/net/wireless/ath/ath12k/hw.c
> +++ b/drivers/net/wireless/ath/ath12k/hw.c
> @@ -1084,7 +1084,7 @@ static const struct ath12k_hw_params ath12k_hw_params[] = {
>  		.download_calib = true,
>  		.supports_suspend = false,
>  		.tcl_ring_retry = true,
> -		.reoq_lut_support = true,
> +		.reoq_lut_support = false,
>  		.supports_shadow_regs = false,
>  
>  		.num_tcl_banks = 48,

Stable team:

The issue with enabling this feature has been fixed in the mainline with:
afcefc58fdfd ("wifi: ath12k: Fix packets received in WBM error ring with REO
LUT enabled")

Hence this patch should not be reverted in the mainline.

But it is difficult to backport that patch, so the original patch should be
reverted in all of the stable trees where it was backported:
6.6, 6.12, 6.15, 6.16

/jeff