From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754104AbbI3SWh (ORCPT ); Wed, 30 Sep 2015 14:22:37 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:59353 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751279AbbI3SWe (ORCPT ); Wed, 30 Sep 2015 14:22:34 -0400 Date: Wed, 30 Sep 2015 19:22:19 +0100 From: Mark Brown To: yitian Cc: lgirdwood@gmail.com, perex@perex.cz, tiwai@suse.com, Andrew.Jackson@arm.com, wsa@the-dreams.de, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Message-ID: <20150930182219.GU15635@sirena.org.uk> References: <006401d0fac5$2e4bb840$8ae328c0$@tangramtek.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="lpUp1egui7PDlNtH" Content-Disposition: inline In-Reply-To: <006401d0fac5$2e4bb840$8ae328c0$@tangramtek.com> X-Cookie: Give him an evasive answer. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 2a01:348:6:8808:7e7a:91ff:fede:4a45 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [RESEND PATCH v2 1/1] ASoC: dwc: fix dma stop transferring issue X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --lpUp1egui7PDlNtH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Sep 29, 2015 at 10:43:17PM +0800, yitian wrote: > Designware I2S uses tx empty and rx available signals as the DMA > handshaking signals. during music playing, if XRUN occurs, > i2s_stop() function will be executed and both tx and rx irq are > masked, when music continues to be played, i2s_start() is executed > but both tx and rx irq are not unmasked which cause I2S stop > sending DMA handshaking signal to DMA controller, and it finally > causes music playing will be stopped once XRUN occurs for the first > time. I'm a bit concerned about how this code ever worked given the above description - is there some race condition which allows things to work if we're lucky? --lpUp1egui7PDlNtH Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWDChaAAoJECTWi3JdVIfQdpAH/jPy5MTvbSOsEvuGL4GxlypV 4AQneDdVjvbE8Iy3zCkb0Wt5n9wuEqRlQUlNUtaqBtfITa2kKUoJspnGaz2jBwf2 2ZB/MKizDcpoxMrYsDVxyumZ+ls8mtugox+5QdzmJNO0SakQ6VjynAWAtI12KRso EmylSuswYojPRRZ0DWP+OPdCB7mE2hX5gZDHF+tt/K79IcW+8CX3MfMpO1cygtDd rNYMabf9CLgcpVoOymTYga1CEDj9p5x3Z2HO6gDov+3qdBSA5Tg7g3OMqpCIXIxe Wju51vEABo5xbjTx7rUt8awDG2NqWaOZf+/hLLJoNn2UyyNUt6aQ0wUp+KSQiAY= =HECV -----END PGP SIGNATURE----- --lpUp1egui7PDlNtH--