From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] ASoC: si476x: Remove custom register I/O implementation Date: Fri, 27 Sep 2013 20:48:16 +0100 Message-ID: <20130927194816.GO19304@sirena.org.uk> References: <1380220461-16359-1-git-send-email-broonie@kernel.org> <20130926194350.GU19304@sirena.org.uk> <20130926205807.GV19304@sirena.org.uk> <20130927100757.GA19304@sirena.org.uk> <20130927170232.GL19304@sirena.org.uk> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1665462682644818670==" Return-path: Received: from cassiel.sirena.org.uk (cassiel.sirena.org.uk [80.68.93.111]) by alsa0.perex.cz (Postfix) with ESMTP id 8A4ED2650C6 for ; Fri, 27 Sep 2013 21:48:22 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Andrey Smirnov Cc: alsa-devel@alsa-project.org, linaro-kernel@lists.linaro.org, Liam Girdwood List-Id: alsa-devel@alsa-project.org --===============1665462682644818670== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="aE2Tjr+Wh4rS13mJ" Content-Disposition: inline --aE2Tjr+Wh4rS13mJ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Sep 27, 2013 at 12:28:14PM -0700, Andrey Smirnov wrote: > That is the case for the V4L driver, in that code the locking is > acquired for logical operations, such "tune" or "power up" rather than > for a single register write, but for the codec driver, to the best of > my knowledge, read and write register are the highest level operations > that it provides. Or am I just unaware of some codec driver > functionality that driver can provide and SoC sound subsystem will use > that would allow the lock to be obtained at higher levels? Since the driver doesn't expose any controls to userspace the only things that can cause register writes are the operations provided by the CODEC driver, they could take the lock for their runtime (which is about the level the v4l stuff is running at AIUI). This still won't fix the issue with the device being powered off but I guess that normal usage patterns will have powered the device up to do tuning or something prior to audio being started. --aE2Tjr+Wh4rS13mJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.21 (GNU/Linux) iQIcBAEBAgAGBQJSReD8AAoJELSic+t+oim9FqwP/A6QZq1C9ftqs/JkofJuQHYD 34feHVb3sl/4XhfhxT+93JrjiP6UMifhOmqJA28aD4q2qVomjJkuzV4ndGkTbAVD nttYWG760ISNx+geHoFzjVQVIN1+khGC4JRn6Uai07H26lqloP0zDnfVmgbSKB7S 7GPVDWPi3uymaRKaKaA00KOamw44nUpXdM8Pm1rl5bF1ID1ZPIfagrwOEO9/H2QY yBAgVYCIN5Fm30K2kEyw09vY78aFYnPG5zd0wV7KQMXXbbbmAeMlD1Sx0L/CSF1z AibcXpcLbSYM4EKgByWJ6olyR/QdwO3/rmMixTerV1k34803n141Juo+Qcj6hmcw 2H3BQ/rVnF5WpxuVwXVC21BaNlcGMd10DkIc0ziMxDVk95wAIKznieg7HXpmoJP5 OBaQk0D0Z06ozOL69PYjOw5PpntSLDlZn8AQjEeeRroyiv5KdgFGcq8IEIEz2sv9 nVD14OT43v7/UHtPs5+2H/uY4oLobBX6ibZFDKfnN4AaFLJXCnZusqkM22lQf+Uw CXUQckyiQgsUX/jZEHwXm/3OBvnNPfupa9DL5+0kuHbMAZHPT4W9FyK7Um/CCt3h kVHmBiF6t62MW3sPJCzZpBFDZBNqz804EPch380P0e2nZ2c1bDWHpShEEo/lNvTc AYnRtSJvMAXTBMk/XrFy =lu95 -----END PGP SIGNATURE----- --aE2Tjr+Wh4rS13mJ-- --===============1665462682644818670== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============1665462682644818670==--