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From: Mark Brown <broonie@kernel.org>
To: "Derek [方德義]" <derek.fang@realtek.com>
Cc: "Oder Chiou" <oder_chiou@realtek.com>,
	"Jack Yu" <jack.yu@realtek.com>,
	"alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
	"lars@metafoo.de" <lars@metafoo.de>,
	"lgirdwood@gmail.com" <lgirdwood@gmail.com>,
	"Albert Chen" <albertchen@realtek.com>,
	"Shuming [范書銘]" <shumingf@realtek.com>,
	"Flove(HsinFu)" <flove@realtek.com>
Subject: Re: [alsa-devel] [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks
Date: Mon, 17 Feb 2020 12:36:50 +0000	[thread overview]
Message-ID: <20200217123650.GD9304@sirena.org.uk> (raw)
In-Reply-To: <b9cfe003aeb34216b59c9a22c4601bf1@realtek.com>


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On Mon, Feb 17, 2020 at 10:59:55AM +0000, Derek [方德義] wrote:
> > Subject: Re: [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks

> > > +	if (parent_rate != CLK_PLL2_FIN)
> > > +		dev_warn(component->dev, "clk %s only support %d Hz input\n",
> > > +			clk_name, CLK_PLL2_FIN);

> > > +	if (rate != CLK_48) {
> > > +		dev_warn(component->dev, "clk %s only support %d Hz output\n",
> > > +			clk_name, CLK_48);
> > > +		rate = CLK_48;
> > > +	}

> > Are these genuine restrictions of the hardware or is this just being
> > hard coded in the driver?

> It's hard coded for an application case.
> Generate a 48kHz clk with a parent 48 MHz clk.

I see...  obviously this is really not good quality of implementation
although it doesn't actually break any external interfaces so I guess we
could take it.  I would at least want to see some clear comments in both
the code and the changelog explaining that this limitation is just a
temporary hack until a better implementation is done though.

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  parent reply	other threads:[~2020-02-17 12:37 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-14  7:53 [alsa-devel] [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks derek.fang
2020-02-14  7:53 ` [alsa-devel] [PATCH 2/2] ASoC: rt5682: Add DAI clock binding info for WCLK/BCLK CCF usage derek.fang
2020-02-14 12:38 ` [alsa-devel] [PATCH 1/2] ASoC: rt5682: Add CCF usage for providing I2S clks Mark Brown
     [not found]   ` <b9cfe003aeb34216b59c9a22c4601bf1@realtek.com>
2020-02-17 12:36     ` Mark Brown [this message]
2020-02-18  6:33       ` Derek [方德義]

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