linux-kernel - Re: [PATCH v2] wifi: rtw89: Print just once for unknown C2H classes

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Message-ID: <198e2e23-5e75-4223-8d85-fba255bc7fd2@linux.dev>
Date: Fri, 1 Aug 2025 10:39:39 -0400
From: Sean Anderson <sean.anderson@...ux.dev>
To: Ping-Ke Shih <pkshih@...ltek.com>,
 "linux-wireless@...r.kernel.org" <linux-wireless@...r.kernel.org>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 Bitterblue Smith <rtl8821cerfe2@...il.com>
Subject: Re: [PATCH v2] wifi: rtw89: Print just once for unknown C2H classes

On 7/31/25 20:30, Ping-Ke Shih wrote:
> Sean Anderson <sean.anderson@...ux.dev> wrote:
>> On 7/29/25 20:36, Ping-Ke Shih wrote:
>> > Sean Anderson <sean.anderson@...ux.dev> wrote:
>> >> There are more unsupported functions than just LOWRT_RTY. Improve on
>> >> commit 3b66519b023b ("wifi: rtw89: phy: add dummy c2h handler to avoid
>> >> warning message") by printing a message just once when we first
>> >> encounter an unsupported class.
>> >
>> > Once I encounter an unsupported class/func, I'll check firmware team if the
>> > C2H events can be ignored. If so, I add a dummy function to avoid the message.
>> > If not, I should add code to handle the event.
>> >
>> > Do you want to see the message even though it only appears once?
>> 
>> I mean, maybe it should just be a debug? Are these messages useful for anyone
>> other than the developers?
> 
> Yes, this could just be a debug. However, developers normally don't turn on
> debug mask, so using rtw89_info is to clearly remind developers to pay
> attention on this lack of C2H handler. And, I suppose developers must handle
> this when they see flooding messages.

Well, regular users get this too. It is really unnecessary to print
thousands of messages when they are completely benign.

>> 
>> Maybe we should just print only the very first unsupported message at info level
>> and print the rest at debug.
> 
> I'm afraid developers will ignore or miss the messages. To reduce messages
> is fine to me , but more important is to look up vendor driver to see if
> the C2H handler is necessary. 

OK, so we should print exactly once for each class/func.

--Sean