Re: [RFC PATCH 00/14] wifi: rtl8xxxu: Add AP mode support for 8188f

[Bitterblue Smith <rtl8821cerfe2@gmail.com>]

On 22/03/2023 19:18, Martin Kaistra wrote:
> This series intends to bring AP mode support to the rtl8xxxu driver,
> more specifically for the 8188f, because this is the HW I have.
> The work is based on the vendor driver as I do not have access to
> datasheets.
> 
> This is an RFC, so that there can be a discussion first before
> potentially implementing support for the other chips in this driver, if
> required.
> 

Hi!

I ran into some problems while testing this.

First, a null pointer dereference in rtl8xxxu_config_filter() when
turning on the AP. priv->vif was NULL:

	if (priv->vif->type != NL80211_IFTYPE_AP) {

I changed it like this:

	if (priv->vif && priv->vif->type != NL80211_IFTYPE_AP) {

Then I was able to turn on the AP and connect my phone to it. However,
the system froze after a few seconds. I had `journalctl --follow`
running. The last thing printed before the system froze was the DHCP
stuff (discover, offer, request, ack). The phone said it was connected,
but speedtest.net didn't have time to load before the freeze.

My system is a laptop with RTL8822CE internal wifi card connected to my
ISP's router. The connections are managed by NetworkManager 1.42.4-1,
which uses wpa_supplicant 2:2.10-8 and dnsmasq 2.89-1. The operating
system is Arch Linux running kernel 6.2.5-arch1-1.

I used Plasma's NetworkManager applet to create a new "Wi-Fi (shared)"
connection with mode "Access Point", band 2.4 GHz, channel 1, no
encryption, and "IPv4 is required for this connection".


Unrelated to anything, just out of curiosity, what brand/model is your
RTL8188FU?