From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Wed, 1 Apr 2015 08:58:24 +0100 Subject: [PATCH RFC 09/11] sound/core: add IEC958 channel status helper In-Reply-To: <551B5213.8070902@rock-chips.com> References: <20150330193911.GM24899@n2100.arm.linux.org.uk> <551A5B2F.50203@rock-chips.com> <20150331091329.GP24899@n2100.arm.linux.org.uk> <551B5213.8070902@rock-chips.com> Message-ID: <20150401075824.GX24899@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Apr 01, 2015 at 10:04:03AM +0800, Yakir wrote: > Hi Russell, > > ? 2015/3/31 17:13, Russell King - ARM Linux ??: > >As for the channel number, this is intentionally left to the driver - > >most cases I've found either the driver isn't interested, or where > >they are interested (the only case I know of is my dw_hdmi ahb audio > >driver), it's more appropriate to generate a baseline channel status, > >and let the driver iterate over the channels adding the appropriate > >channel number in. > Okay, agree with you to keep baseline channel status, but seems dw_hdmi > i2s audio are interested in channle number (to fill in schnl resigeters). Correct - but it's pointless having it in this helper as I explained. Please read my dw_hdmi-ahb-audio code to see why. It would be wasteful to memset the structure back to zero, only to re-fill it with exactly the same data except for the channel number. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.