From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [alsa-devel] [PATCH v2 3/3] ASoC: TDA7802: Add turn-on diagnostic routine Date: Fri, 2 Aug 2019 18:27:56 +0100 Message-ID: <20190802172756.GC5387@sirena.org.uk> References: <20190730120937.16271-1-thomas.preston@codethink.co.uk> <20190730120937.16271-4-thomas.preston@codethink.co.uk> <20190730141935.GF4264@sirena.org.uk> <45156592-a90f-b4f8-4d30-9631c03f1280@codethink.co.uk> <20190730155027.GJ4264@sirena.org.uk> <9b47a360-3b62-b968-b8d5-8639dc4b468d@codethink.co.uk> <20190801234241.GG5488@sirena.org.uk> <472cc4ee-2e80-8b08-d842-79c65df572f3@codethink.co.uk> <20190802111036.GB5387@sirena.org.uk> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="2JFBq9zoW8cOFH7v" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Thomas Preston Cc: Mark Rutland , devicetree@vger.kernel.org, alsa-devel@alsa-project.org, Charles Keepax , Kuninori Morimoto , Kirill Marinushkin , Liam Girdwood , Marco Felsch , Annaliese McDermond , Takashi Iwai , Paul Cercueil , Vinod Koul , Rob Herring , Srinivas Kandagatla , Jerome Brunet , linux-kernel@vger.kernel.org, Cheng-Yi Chiang List-Id: devicetree@vger.kernel.org --2JFBq9zoW8cOFH7v Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Aug 02, 2019 at 03:51:09PM +0100, Thomas Preston wrote: > On 02/08/2019 12:10, Mark Brown wrote: > > You can use a read only control for the readback, or just have it be > > triggered by overwriting the readback value. You can cache the result. > Keeping the trigger and result together like that would be better I think, > although the routine isn't supposed to run mid way through playback. If > we're mid playback the debugfs routine has to turn off AMP_ON, take the > device back to a known state, run diagnostics, then restore. Which causes > a gap in the audible sound. Whatever method is used to do the triggering can always return -EBUSY when you someone tries to do so during playback. > >> Kirill Marinushkin mentioned this in the first review [0], it just did= n't > >> really sink in until now! > > You could do that too, yeah. Depends on what this is diagnosing and if > > that'd be useful. > The diagnostic status bits describe situations such as: > - open load (no speaker connected) > - short to GND > - short to VCC > - etc > The intention is to test if all the speakers are connected. So, one might= =20 > have a self test which runs the diagnostic and verifies it outputs: =2E.. > I think the module parameter method is more appropriate for a > "Turn-on diagnostic", even though I don't really like grepping dmesg > for the result. I'll go ahead and implement that unless anyone has a > particular preference for the kcontrol-trigger. Right. It's not ideal for use in production systems for example but perhaps fine for support techs or whoever. Up to you anyway. --2JFBq9zoW8cOFH7v Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl1EcpsACgkQJNaLcl1U h9APwgf/Q4KWsYkJw+Dyy8wm8pDjOkyVsUY1B9NZLLVp7mVndWT2ywIcipH0hV+Q DeDX02ZUjkRup/AwNN/Ptwcy4GHnREbe7g6sJPgAtPFtXcuzUCJdUJsLDt4oXl5f Nk2TjjELzuKqFz1E1zkIl8h1CowLDljJRTgCOp7mOhmT+x6kCjvURDzhkcXYPiib wj2Rcu4thxX+oVvl7YkOpd0Wv+ZNGyM+8gEpjI22sy2MVjpMLT9SmzMp4OdfgT0h dRVXoXKFIDT5zDpQEteTsuJdIS+NlBGM6yfKQ1fRu/+2gSh78+c/4dfT79d/h2ui 1ZJ5R45/kE4lb4xqQ2+hfM6IeKQQZQ== =kN6B -----END PGP SIGNATURE----- --2JFBq9zoW8cOFH7v--