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

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Message-ID: <b4a69a44-bb9d-4c1d-b628-9204ed8c623e@linux.dev>
Date: Thu, 31 Jul 2025 16:16:58 -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 7/29/25 23:42, Ping-Ke Shih wrote:
> Ping-Ke Shih <pkshih@...ltek.com> 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?
>> 
>> > Do the same for each unsupported func of
>> > the supported classes. This prevents messages like
>> >
>> > rtw89_8922ae 0000:81:00.0: PHY c2h class 2 not support
> 
> Is this a real example?

This is a real example.

> We have handled class 2 (RTW89_PHY_C2H_CLASS_DM), no?

If func != RTW89_PHY_C2H_DM_FUNC_LOWRT_RTY then we fall through to the
default case.

> Please point out the class / func you encountered. Then I can look up vendor
> driver or contact internal firmware team to know if we should implement or
> just add a dummy function.
> 
> If we defer it, I don't know when we can do it. 

rtw89_8922ae 0000:81:00.0: PHY c2h class 2 func 12 not supported

But the func was not printed in the base kernel, just the class.

--Sean

>> >
>> > from filling up dmesg.
>> >
>> > Signed-off-by: Sean Anderson <sean.anderson@...ux.dev>
>> > ---
>> >
>> > Changes in v2:
>> > - Also suppress unsupported func messages
>> >
>> >  drivers/net/wireless/realtek/rtw89/phy.c | 18 +++++++++++++++---
>> >  1 file changed, 15 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/drivers/net/wireless/realtek/rtw89/phy.c b/drivers/net/wireless/realtek/rtw89/phy.c
>> > index f4eee642e5ce..9484d80eea9b 100644
>> > --- a/drivers/net/wireless/realtek/rtw89/phy.c
>> > +++ b/drivers/net/wireless/realtek/rtw89/phy.c
>> > @@ -3535,17 +3535,25 @@ void rtw89_phy_c2h_handle(struct rtw89_dev *rtwdev, struct sk_buff *skb,
>> >  {
>> >         void (*handler)(struct rtw89_dev *rtwdev,
>> >                         struct sk_buff *c2h, u32 len) = NULL;
>> > +       static DECLARE_BITMAP(printed_ra, U8_MAX);
>> > +       static DECLARE_BITMAP(printed_rfk_log, U8_MAX);
>> > +       static DECLARE_BITMAP(printed_rfk_report, U8_MAX);
>> > +       static DECLARE_BITMAP(printed_class, U8_MAX);
>> > +       unsigned long *printed;
>> >
>> >         switch (class) {
>> >         case RTW89_PHY_C2H_CLASS_RA:
>> > +               printed = printed_ra;
>> >                 if (func < RTW89_PHY_C2H_FUNC_RA_MAX)
>> >                         handler = rtw89_phy_c2h_ra_handler[func];
>> >                 break;
>> >         case RTW89_PHY_C2H_RFK_LOG:
>> > +               printed = printed_rfk_log;
>> >                 if (func < ARRAY_SIZE(rtw89_phy_c2h_rfk_log_handler))
>> >                         handler = rtw89_phy_c2h_rfk_log_handler[func];
>> >                 break;
>> >         case RTW89_PHY_C2H_RFK_REPORT:
>> > +               printed = printed_rfk_report;
>> >                 if (func < ARRAY_SIZE(rtw89_phy_c2h_rfk_report_handler))
>> >                         handler = rtw89_phy_c2h_rfk_report_handler[func];
>> >                 break;
>> > @@ -3554,12 +3562,16 @@ void rtw89_phy_c2h_handle(struct rtw89_dev *rtwdev, struct sk_buff *skb,
>> >                         return;
>> >                 fallthrough;
>> >         default:
>> > -               rtw89_info(rtwdev, "PHY c2h class %d not support\n", class);
>> > +               if (!test_and_set_bit(class, printed_class))
>> > +                       rtw89_info(rtwdev, "PHY c2h class %d not supported\n",
>> > +                                  class);
>> >                 return;
>> >         }
>> >         if (!handler) {
>> > -               rtw89_info(rtwdev, "PHY c2h class %d func %d not support\n", class,
>> > -                          func);
>> > +               if (!test_and_set_bit(func, printed))
>> > +                       rtw89_info(rtwdev,
>> > +                                  "PHY c2h class %d func %d not supported\n",
>> > +                                  class, func);
>> >                 return;
>> >         }
>> >         handler(rtwdev, skb, len);
>> > --
>> > 2.35.1.1320.gc452695387.dirty
>