linux-kernel - Re: [PATCH 23/25] ASoC: sun8i-codec: Generalize AIF clock control

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20201012111722.vhrzbkxuf5suxges@gilmour.lan>
Date:   Mon, 12 Oct 2020 13:17:22 +0200
From:   Maxime Ripard <maxime@...no.tech>
To:     Samuel Holland <samuel@...lland.org>
Cc:     Mark Brown <broonie@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Chen-Yu Tsai <wens@...e.org>, Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>,
        Ondrej Jirman <megous@...ous.com>, alsa-devel@...a-project.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 23/25] ASoC: sun8i-codec: Generalize AIF clock control

On Mon, Oct 05, 2020 at 11:51:08PM -0500, Samuel Holland wrote:
> On 10/5/20 7:04 AM, Maxime Ripard wrote:
> > Hi,
> > 
> > On Wed, Sep 30, 2020 at 09:11:46PM -0500, Samuel Holland wrote:
> >> The AIF clock control register has the same layout for all three AIFs.
> >> The only difference between them is that AIF3 is missing some fields. We
> >> can reuse the same register field definitions for all three registers,
> >> and use the DAI ID to select the correct register address.
> >>
> >> Signed-off-by: Samuel Holland <samuel@...lland.org>
> >> ---
> >>  sound/soc/sunxi/sun8i-codec.c | 64 +++++++++++++++++++----------------
> >>  1 file changed, 34 insertions(+), 30 deletions(-)
> >>
> >> diff --git a/sound/soc/sunxi/sun8i-codec.c b/sound/soc/sunxi/sun8i-codec.c
> >> index 032a3f714dbb..1c34502ac47a 100644
> >> --- a/sound/soc/sunxi/sun8i-codec.c
> >> +++ b/sound/soc/sunxi/sun8i-codec.c
> >> @@ -37,23 +37,23 @@
> >>  #define SUN8I_MOD_CLK_ENA_DAC				2
> >>  #define SUN8I_MOD_RST_CTL				0x014
> >>  #define SUN8I_MOD_RST_CTL_AIF1				15
> >>  #define SUN8I_MOD_RST_CTL_ADC				3
> >>  #define SUN8I_MOD_RST_CTL_DAC				2
> >>  #define SUN8I_SYS_SR_CTRL				0x018
> >>  #define SUN8I_SYS_SR_CTRL_AIF1_FS			12
> >>  #define SUN8I_SYS_SR_CTRL_AIF2_FS			8
> >> -#define SUN8I_AIF1CLK_CTRL				0x040
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_MSTR_MOD		15
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_CLK_INV			13
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_BCLK_DIV		9
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_LRCK_DIV		6
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_WORD_SIZ		4
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_DATA_FMT		2
> >> +#define SUN8I_AIF_CLK_CTRL(n)				(0x040 * (1 + (n)))
> >> +#define SUN8I_AIF_CLK_CTRL_MSTR_MOD			15
> >> +#define SUN8I_AIF_CLK_CTRL_CLK_INV			13
> >> +#define SUN8I_AIF_CLK_CTRL_BCLK_DIV			9
> >> +#define SUN8I_AIF_CLK_CTRL_LRCK_DIV			6
> >> +#define SUN8I_AIF_CLK_CTRL_WORD_SIZ			4
> >> +#define SUN8I_AIF_CLK_CTRL_DATA_FMT			2
> >>  #define SUN8I_AIF1_ADCDAT_CTRL				0x044
> >>  #define SUN8I_AIF1_ADCDAT_CTRL_AIF1_AD0L_ENA		15
> >>  #define SUN8I_AIF1_ADCDAT_CTRL_AIF1_AD0R_ENA		14
> >>  #define SUN8I_AIF1_ADCDAT_CTRL_AIF1_AD0L_SRC		10
> >>  #define SUN8I_AIF1_ADCDAT_CTRL_AIF1_AD0R_SRC		8
> >>  #define SUN8I_AIF1_DACDAT_CTRL				0x048
> >>  #define SUN8I_AIF1_DACDAT_CTRL_AIF1_DA0L_ENA		15
> >>  #define SUN8I_AIF1_DACDAT_CTRL_AIF1_DA0R_ENA		14
> >> @@ -83,21 +83,21 @@
> >>  #define SUN8I_DAC_MXR_SRC_DACR_MXR_SRC_AIF1DA1R		10
> >>  #define SUN8I_DAC_MXR_SRC_DACR_MXR_SRC_AIF2DACR		9
> >>  #define SUN8I_DAC_MXR_SRC_DACR_MXR_SRC_ADCR		8
> >>  
> >>  #define SUN8I_SYSCLK_CTL_AIF1CLK_SRC_MASK	GENMASK(9, 8)
> >>  #define SUN8I_SYSCLK_CTL_AIF2CLK_SRC_MASK	GENMASK(5, 4)
> >>  #define SUN8I_SYS_SR_CTRL_AIF1_FS_MASK		GENMASK(15, 12)
> >>  #define SUN8I_SYS_SR_CTRL_AIF2_FS_MASK		GENMASK(11, 8)
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_CLK_INV_MASK	GENMASK(14, 13)
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_BCLK_DIV_MASK	GENMASK(12, 9)
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_LRCK_DIV_MASK	GENMASK(8, 6)
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_WORD_SIZ_MASK	GENMASK(5, 4)
> >> -#define SUN8I_AIF1CLK_CTRL_AIF1_DATA_FMT_MASK	GENMASK(3, 2)
> >> +#define SUN8I_AIF_CLK_CTRL_CLK_INV_MASK		GENMASK(14, 13)
> >> +#define SUN8I_AIF_CLK_CTRL_BCLK_DIV_MASK	GENMASK(12, 9)
> >> +#define SUN8I_AIF_CLK_CTRL_LRCK_DIV_MASK	GENMASK(8, 6)
> >> +#define SUN8I_AIF_CLK_CTRL_WORD_SIZ_MASK	GENMASK(5, 4)
> >> +#define SUN8I_AIF_CLK_CTRL_DATA_FMT_MASK	GENMASK(3, 2)
> >>  
> >>  #define SUN8I_CODEC_PASSTHROUGH_SAMPLE_RATE 48000
> >>  
> >>  #define SUN8I_CODEC_PCM_FORMATS	(SNDRV_PCM_FMTBIT_S8     |\
> >>  				 SNDRV_PCM_FMTBIT_S16_LE |\
> >>  				 SNDRV_PCM_FMTBIT_S20_LE |\
> >>  				 SNDRV_PCM_FMTBIT_S24_LE |\
> >>  				 SNDRV_PCM_FMTBIT_S20_3LE|\
> >> @@ -223,32 +223,34 @@ static int sun8i_codec_update_sample_rate(struct sun8i_codec *scodec)
> >>  			   hw_rate << SUN8I_SYS_SR_CTRL_AIF1_FS);
> >>  
> >>  	return 0;
> >>  }
> >>  
> >>  static int sun8i_codec_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
> >>  {
> >>  	struct sun8i_codec *scodec = snd_soc_dai_get_drvdata(dai);
> >> +	u32 reg = SUN8I_AIF_CLK_CTRL(dai->id);
> >>  	u32 format, invert, value;
> >>  
> >>  	/* clock masters */
> >>  	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
> >>  	case SND_SOC_DAIFMT_CBS_CFS: /* Codec slave, DAI master */
> >>  		value = 0x1;
> >>  		break;
> >>  	case SND_SOC_DAIFMT_CBM_CFM: /* Codec Master, DAI slave */
> >>  		value = 0x0;
> >>  		break;
> >>  	default:
> >>  		return -EINVAL;
> >>  	}
> >> -	regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL,
> >> -			   BIT(SUN8I_AIF1CLK_CTRL_AIF1_MSTR_MOD),
> >> -			   value << SUN8I_AIF1CLK_CTRL_AIF1_MSTR_MOD);
> >> +
> >> +	regmap_update_bits(scodec->regmap, reg,
> >> +			   BIT(SUN8I_AIF_CLK_CTRL_MSTR_MOD),
> >> +			   value << SUN8I_AIF_CLK_CTRL_MSTR_MOD);
> > 
> > I guess it would be more readable without the intermediate variable to
> > store the register.
> 
> You mean you want me to call `SUN8I_AIF_CLK_CTRL(dai->id)` in each
> regmap_update_bits call?

Yep

> I don't know that the compiler could optimize that due to the pointer
> read. And how would you suggest handling patch 25, where sometimes
> AIF3 needs to write to AIF2's clock register?

I'm not sure the compiler optimisation really matters anyway. It's not
really a fast path, and assuming it does the multiplication every time,
it will still be completely negligible compared to other operations done
in that function (starting with regmap_update_bits).

Maxime

Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)