From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Sat, 9 May 2015 17:55:36 +0100 Subject: [alsa-devel] [PATCH 12/13] drm: bridge/dw_hdmi-ahb-audio: add audio driver In-Reply-To: <554E3AA8.8060601@iki.fi> References: <20150509102501.GO2067@n2100.arm.linux.org.uk> <554E3AA8.8060601@iki.fi> Message-ID: <20150509165536.GS2067@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, May 09, 2015 at 07:49:44PM +0300, Anssi Hannula wrote: > (Of course having userspace set them requires that the device has a > proper entry in /usr/share/alsa/cards and the pcm device is accessed via > the standard "hdmi" or "iec958" device names which perform the channel > status word setup. I guess the ARM SoC stuff generally doesn't bother > with that, explaining a bit why some kernel drivers set them by themselves). I'm not sure that's sufficient - I haven't yet found where in the ALSA userspace, the AES bits are appropriately set according to the sample rate. > HDMI_FC_AUDICONF2 register default value is 0x00, which means plain > stereo (per CEA-861). If this is what goes on to the HDMI link as well, > the audio sink should ignore the other channels. > Did you check that multichannel PCM actually works? (maybe I'm just > missing where CA is set) I have no way to test multichannel support - not everyone has a plethora of HDMI devices readily accessible. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.