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From:   Kalle Valo <kvalo@kernel.org>
To:     Ping-Ke Shih <pkshih@realtek.com>
Cc:     "linux-wireless\@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH 5/5] wifi: rtw89: use struct to access register-based H2C/C2H
References: <20230522122513.13559-1-pkshih@realtek.com>
        <20230522122513.13559-6-pkshih@realtek.com>
        <87cz2ol7i5.fsf@kernel.org>
        <709fd6a89f3f4a637410c0974b32154a8a1b89fe.camel@realtek.com>
Date:   Fri, 26 May 2023 14:49:12 +0300
In-Reply-To: <709fd6a89f3f4a637410c0974b32154a8a1b89fe.camel@realtek.com>
        (Ping-Ke Shih's message of "Fri, 26 May 2023 11:46:21 +0000")
Message-ID: <87y1lbjosn.fsf@kernel.org>
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Ping-Ke Shih <pkshih@realtek.com> writes:

> On Thu, 2023-05-25 at 19:07 +0300, Kalle Valo wrote:
>
>> 
>> Ping-Ke Shih <pkshih@realtek.com> writes:
>> 
>> > The register-based H2C/C2H are used to exchange commands and events with
>> > firmware. The exchange data is limited, but it is relatively simple,
>> > because it can work before HCI initialization. To make these code clean,
>> > use struct to access them. This patch doesn't change logic at all.
>> > 
>> > Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
>> 
>> [...]
>> 
>> > --- a/drivers/net/wireless/realtek/rtw89/fw.h
>> > +++ b/drivers/net/wireless/realtek/rtw89/fw.h
>> > @@ -18,15 +18,51 @@ enum rtw89_fw_dl_status {
>> >       RTW89_FWDL_WCPU_FW_INIT_RDY = 7
>> >  };
>> > 
>> > -#define RTW89_GET_C2H_HDR_FUNC(info) \
>> > -     u32_get_bits(info, GENMASK(6, 0))
>> > -#define RTW89_GET_C2H_HDR_LEN(info) \
>> > -     u32_get_bits(info, GENMASK(11, 8))
>> > +struct rtw89_c2hreg_hdr {
>> > +     u32 w0;
>> > +};
>> 
>> Why this is u32? Shouldn't it be __le32?
>> 
>> > +#define RTW89_C2HREG_HDR_FUNC_MASK GENMASK(6, 0)
>> > +#define RTW89_C2HREG_HDR_ACK BIT(7)
>> > +#define RTW89_C2HREG_HDR_LEN_MASK GENMASK(11, 8)
>> > +#define RTW89_C2HREG_HDR_SEQ_MASK GENMASK(15, 12)
>> > +
>> > +struct rtw89_c2hreg_phycap {
>> > +     u32 w0;
>> > +     u32 w1;
>> > +     u32 w2;
>> > +     u32 w3;
>> > +} __packed;
>> 
>> Here as well? And I saw more in the patch.
>> 
>> Of course these were already there so isn't a problem introduced by this
>> patchset, but I started wondering if we are missing some little endian
>> types?
>> 
>
> I had the same question as yours when I did this conversion, but they
> are correct because we access these H2C commands/C2H events via registers
> which are CPU order.

Ah, thanks for the explanation.

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