RE: [PATCH rtw-next 1/2] wifi: rtw88: usb: Reduce control message timeout to 500 ms

[Ping-Ke Shih <pkshih@realtek.com>]

Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:
> RTL8811AU stops responding during the firmware download on some systems:
> 
> [  809.256440] rtw_8821au 5-2.1:1.0: Firmware version 42.4.0, H2C version 0
> [  812.759142] rtw_8821au 5-2.1:1.0 wlp48s0f4u2u1: renamed from wlan0
> [  837.315388] rtw_8821au 1-4:1.0: write register 0x1ef4 failed with -110
> [  867.524259] rtw_8821au 1-4:1.0: write register 0x1ef8 failed with -110
> [  868.930976] rtw_8821au 5-2.1:1.0 wlp48s0f4u2u1: entered promiscuous mode
> [  897.730952] rtw_8821au 1-4:1.0: write register 0x1efc failed with -110
> 
> Each write takes 30 seconds to fail because that's the timeout currently
> used for control messages in rtw_usb_write().
> 
> In this scenario the firmware download takes at least 2000 seconds.
> Because this is done from the USB probe function, the long delay makes
> other things in the system hang.
> 
> Reduce the timeout to 500 ms. This is the value used by the official USB
> wifi drivers from Realtek.

A question about timeout time. Is this enough for USB 2 or older?

> 
> Of course this only makes things hang for ~30 seconds instead of ~30
> minutes. It doesn't fix the firmware download.
> 
> Tested with RTL8822CU, RTL8812BU, RTL8811CU, RTL8814AU, RTL8811AU,
> RTL8812AU, RTL8821AU, RTL8723DU.
> 
> Cc: stable@vger.kernel.org
> Fixes: a82dfd33d123 ("wifi: rtw88: Add common USB chip support")
> Link: https://github.com/lwfinger/rtw88/issues/344
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>

Acked-by: Ping-Ke Shih <pkshih@realtek.com>