From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH 2/7] drm/edid: Allow to ignore the audio EDID data Date: Wed, 6 Mar 2019 09:52:39 +0100 Message-ID: <20190306085239.r7ustlm2bzav2m4k@flea> References: <4914bea9fc3ef3deaffa39ab691dbd9a76461e97.1551711042.git-series.maxime.ripard@bootlin.com> <87wole76ws.fsf@anholt.net> <20190305091240.sbkvdwosocaytx22@flea> <87woldm1s5.fsf@anholt.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0474223877==" Return-path: Received: from relay1-d.mail.gandi.net (relay1-d.mail.gandi.net [217.70.183.193]) by gabe.freedesktop.org (Postfix) with ESMTPS id 191E66E101 for ; Wed, 6 Mar 2019 08:52:43 +0000 (UTC) In-Reply-To: <87woldm1s5.fsf@anholt.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Eric Anholt Cc: eben@raspberrypi.org, David Airlie , Maling list - DRI developers , Paul Kocialkowski , Sean Paul , Thomas Petazzoni , Daniel Vetter , linux-arm-kernel List-Id: dri-devel@lists.freedesktop.org --===============0474223877== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="nz2is7cs3fne3fxy" Content-Disposition: inline --nz2is7cs3fne3fxy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Mar 05, 2019 at 01:47:38PM -0800, Eric Anholt wrote: > Maxime Ripard writes: >=20 > > [ Unknown signature status ] > > On Mon, Mar 04, 2019 at 03:05:31PM -0500, Alex Deucher wrote: > >> On Mon, Mar 4, 2019 at 2:53 PM Eric Anholt wrote: > >> > > >> > Maxime Ripard writes: > >> > > >> > > In some cases, in order to accomodate with displays with poor EDID= s, we > >> > > need to ignore that the monitor alledgedly supports audio output a= nd > >> > > disable the audio output. > >> > > > >> > > Signed-off-by: Maxime Ripard > >> > > --- > >> > > drivers/gpu/drm/drm_edid.c | 8 ++++++++ > >> > > 1 file changed, 8 insertions(+) > >> > > > >> > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid= =2Ec > >> > > index 990b1909f9d7..c0258b011bb2 100644 > >> > > --- a/drivers/gpu/drm/drm_edid.c > >> > > +++ b/drivers/gpu/drm/drm_edid.c > >> > > @@ -4190,6 +4190,11 @@ bool drm_detect_hdmi_monitor(struct edid *e= did) > >> > > } > >> > > EXPORT_SYMBOL(drm_detect_hdmi_monitor); > >> > > > >> > > +static bool ignore_edid_audio =3D false; > >> > > +module_param(ignore_edid_audio, bool, 0644); > >> > > +MODULE_PARM_DESC(ignore_edid_audio, > >> > > + "Ignore the EDID and always consider that a monitor= doesn't have audio capabilities"); > >> > > + > >> > > /** > >> > > * drm_detect_monitor_audio - check monitor audio capability > >> > > * @edid: EDID block to scan > >> > > @@ -4209,6 +4214,9 @@ bool drm_detect_monitor_audio(struct edid *e= did) > >> > > bool has_audio =3D false; > >> > > int start_offset, end_offset; > >> > > > >> > > + if (ignore_edid_audio) > >> > > + goto end; > >> > > + > >> > > edid_ext =3D drm_find_cea_extension(edid); > >> > > if (!edid_ext) > >> > > goto end; > >> > > >> > It looks like the motivation for the original flag on Raspberry Pi w= as > >> > "I've got a non-audio monitor, but the system comes up trying to play > >> > audio to HDMI instead of the analog jack". Do we have some way for = DRM > >> > to communicate to ALSA that this is not the right place to try to pl= ay > >> > audio by default? > >>=20 > >> Apparently not. We have users using debug knobs in our drivers to > >> disable display audio because ALSA defaults to that rather than other > >> audio. > > > > I guess one way to do this would be to register the card only when an > > audio-capable monitor is connected instead of doing this at probe > > time. I'm not sure how convenient it is for userspace though. >=20 > Oh, right, the HDMI encoder passes the ELD to ALSA, and userspace gets > to use that. So, open source is already doing the right thing, and the > problem was that the old driver talking to the firmware wouldn't, thus > the need for a flag. Ok, I'll drop that patch then. Thanks! Maxime --=20 Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --nz2is7cs3fne3fxy Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXH+KVwAKCRDj7w1vZxhR xZN2AQCt8mnCseiW2ITU4+Oc3kZiNnnyHzi8VLSt0AQKRjhKHAEAjx2tRDHtVJbM jtZHaNkxsZvFduqSgSaBKbovdPmh+wA= =s7LK -----END PGP SIGNATURE----- --nz2is7cs3fne3fxy-- --===============0474223877== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVs --===============0474223877==--