From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH v3 04/14] ASoC: SOF: Add support for IPC IO between DSP and Host Date: Tue, 22 Jan 2019 21:13:19 +0000 Message-ID: <20190122211319.GP7579@sirena.org.uk> References: <20181211212318.28644-1-pierre-louis.bossart@linux.intel.com> <20181211212318.28644-5-pierre-louis.bossart@linux.intel.com> <20190109203720.GQ10405@sirena.org.uk> <876df209-c829-873e-047e-c73fb0579d68@linux.intel.com> <20190122190425.GJ7579@sirena.org.uk> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============3853931687183745413==" Return-path: 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: Pierre-Louis Bossart Cc: alsa-devel@alsa-project.org, andriy.shevchenko@intel.com, tiwai@suse.de, Jie Yang , Daniel Baluta , liam.r.girdwood@linux.intel.com, vkoul@kernel.org, Alan Cox , sound-open-firmware@alsa-project.org List-Id: alsa-devel@alsa-project.org --===============3853931687183745413== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="sGwo475CiIwWEjLI" Content-Disposition: inline --sGwo475CiIwWEjLI Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Jan 22, 2019 at 03:05:23PM -0600, Pierre-Louis Bossart wrote: > On 1/22/19 1:04 PM, Mark Brown wrote: > > On Thu, Jan 10, 2019 at 02:11:32PM -0600, Pierre-Louis Bossart wrote: > > > Messages can be as big as the mailbox, which is hardware dependent. It could > > > be from a few bytes to a larger e.g. 4k page or more, and indeed we need to > > > keep the lock. > > Is this copying into an actual mailbox or into some data structure in > > memory? It looked like it's copying into a buffer for sending rather > > than the mailbox. > I realize between your feedback and Daniel's that we have a terminology > issue. On the Intel side we don't have a dedicated hardware mailbox unit, > it's only doorbell registers and shared memory windows. Ah, that's what I thought was going on. What I was expecting was a sequence of operations along the lines of: 1. Allocate a buffer for the message. 2. Fill in the message. 3. Mark the message as readable by the DSP. so you only need locking for steps 1 and 3 (and a similar path on return). --sGwo475CiIwWEjLI Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlxHh24ACgkQJNaLcl1U h9Cj6gf+I+bgOQzZZY4cIVkQkmcSdrMgW3hU33zACcJlfnVOrQrvUU8FNXV7YAvq Q1Z3uyIegBtYLb9oKWoQ05ln6kFXwh3sHsenpHqp+mjpUNleyeednRHsrlA3RV5W SpMJ9/EhB28mK+BcpL3zXDTDaG64NhOurZgJpZJLasrMN4Bt6kXokPFxOrbIydLa cqXzYTiFpT2RPHfLjApBbuWm0/mS4yG7WCQ0gVL1cRcZTIK0J2CynRYwcNcpsfci oAU4eiU230/NG9g5dgeUwjK+JuRf1F2XUTiJNEsJ+kkxNGFOyPjvGOkUyfawcv5X o4fFYoV9CCaYgCxbgcQx4F1+FDmhcA== =AyGC -----END PGP SIGNATURE----- --sGwo475CiIwWEjLI-- --===============3853931687183745413== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============3853931687183745413==--