RE: [PATCH v3] wifi: rtw88: increase TX report timeout to fix race condition

[Ping-Ke Shih]

luka.gejak@xxxxxxxxx <luka.gejak@xxxxxxxxx> wrote:
> From: Luka Gejak <luka.gejak@xxxxxxxxx>
> 
> The driver expects the firmware to report TX status within 500ms.
> However, a timeout can be triggered when the hardware performs
> background scans while under TX load. During these scans, the firmware
> stays off-channel for periods exceeding 500ms, delaying the delivery of
> TX reports back to the driver.
> 
> When this occurs, the purge timer fires prematurely and drops the
> tracking skbs from the queue. This results in the host stack
> interpreting the missing status as packet loss, leading to TCP window
> collapse. In testing with iperf3, this causes throughput to drop from
> ~90 Mbps to near-zero for approximately 2 seconds until the connection
> recovers.
> 
> Increase RTW_TX_PROBE_TIMEOUT to 2500ms for RTL8723DU. This duration is
> sufficient to accommodate off-channel dwell time during full background
> scans, ensuring the purge timer only trips during genuine firmware
> lockups and preventing unnecessary TCP retransmission cycles.
> 
> Fixes: a82dfd33d123 ("wifi: rtw88: Add common USB chip support")

Since RTL8723DU is supported by the commit 87caeef032fc, I'd change Fixes
to below during getting merged.

Fixes: 87caeef032fc ("wifi: rtw88: Add rtw8723du chipset support")

> Cc: stable@xxxxxxxxxxxxxxx
> Tested-by: Luka Gejak <luka.gejak@xxxxxxxxx>
> Signed-off-by: Luka Gejak <luka.gejak@xxxxxxxxx>

Acked-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>