RE: [PATCH v7 4/6] wifi: rtw88: sdio: track free TX pages and OQT credits for RTL8723BS

[Luka Gejak <luka.gejak@linux.dev>]

On August 25, 2026 9:50:05 AM GMT+02:00, Ping-Ke Shih <pkshih@realtek.com> wrote:
>Luka Gejak <luka.gejak@linux.dev> wrote:
>> On August 25, 2026 9:25:13 AM GMT+02:00, Ping-Ke Shih <pkshih@realtek.com> wrote:
>> >Luka Gejak <luka.gejak@linux.dev> wrote:
>> >> Hi Ping-Ke,
>> >>
>> >> On August 25, 2026 8:12:58 AM GMT+02:00, Ping-Ke Shih <pkshih@realtek.com> wrote:
>> >> > guard(mutex)(&rtwsdio->tx_credit_lock);
>> >>
>> >> The lock is only taken for this chip, and guard() is unconditional, so I
>> >> split the locked region into its own function instead of branching around
>> >> the lock:
>> >>
>> >>         if (!rtw_is_8723bs(rtwdev)) {
>> >>                 txsize = sdio_align_size(rtwsdio->sdio_func, skb->len);
>> >>
>> >>                 ret = rtw_sdio_check_free_txpg(rtwdev, queue, txsize);
>> >>                 if (ret)
>> >>                         return ret;
>> >>
>> >>                 return rtw_sdio_write_to_port(rtwdev, skb, queue, txaddr,
>> >>                                               txsize);
>> >>         }
>> >>         ...
>> >>         guard(mutex)(&rtwsdio->tx_credit_lock);
>> >>
>> >>         return rtw_sdio_8723bs_write_port(rtwdev, skb, queue, txaddr, txsize,
>> >>                                           write_size);
>> >
>> >I meant
>> >
>> >    if (rtw_is_8723bs(rtwdev))
>> >        guard(mutex)(&rtwsdio->tx_credit_lock);
>> >
>> >Doesn't it work?
>> >
>> >
>> 
>> I tried it, and no. guard() expands to a declaration, and a declaration
>> cannot be the body of an if, so it does not build:
>> 
>>   sdio.c: In function 'rtw_sdio_write_port':
>>   include/linux/cleanup.h:302:9: error: expected expression before
>>   'class_mutex_t'
>>     302 |         class_##_name##_t var __cleanup(...) =
>> 
>> Adding braces builds cleanly, which is the more dangerous version, because
>> the cleanup then runs at the closing brace and the mutex is released again
>> before any of the code it is meant to protect runs.
>> 
>> That is why I moved the locked part into its own function: the guard needs
>> a scope that is exactly the critical section, and an if body is either too
>> small or not allowed.
>
>Okay. Got it.
>
>
Do you mind answering this question, it seems like you missed it:

The unaligned SKB warning now sits in both callers rather than once inside
rtw_sdio_write_to_port(), because __func__ would otherwise report
rtw_sdio_write_to_port for every other SDIO chip where it reports
rtw_sdio_write_port today. Keeping that message identical costs three
duplicated lines. Putting it once in rtw_sdio_write_to_port() is the
tidier code and arguably the more accurate message, at the price of
changing a log line on chips this series is not about. I went with the
duplicate to leave the other parts alone, but I have no strong feeling
either way, so say which you prefer.