From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: i2c_transfer & dma Date: Thu, 25 Sep 2014 16:05:05 +0200 Message-ID: <20140925140505.GA1316@katana> References: <201409232138.33067.PeterHuewe@gmx.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="sm4nu43k4a2Rpi4c" Return-path: Content-Disposition: inline In-Reply-To: <201409232138.33067.PeterHuewe-Mmb7MZpHnFY@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter =?utf-8?B?SMO8d2U=?= Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --sm4nu43k4a2Rpi4c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > So the question is - does the user of i2c_transfer have to provide a dma-= able=20 > buffer, or is the bus driver (like the robotfuzz one) expected to convert= =20 > incoming buffer into a dma-able buffer? As of now, this is an open question, sadly. I have a tendency to leave it to the drivers (maybe with helper functions from the core), because I2C and DMA is so uncommon. I need to work on I2C & DMA next month anyhow, so I hope to dive into that topic, too. No promises, though. If you want to look into it already, please go ahead. The issue was raised here, too: http://patchwork.ozlabs.org/patch/220137/ --sm4nu43k4a2Rpi4c Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUJCERAAoJEBQN5MwUoCm2/aUQAKTKYeahFvwPg65Ar4bGoL8/ YRaRcy7MLHdk4W2YO+HBeseypQUeZ9qmkMlTEYvpdlzVR2G/WW4lYP7Z3jWjh68k z2DDv6/YMZO7N3bwjYdW4gV4tHa2+Xx/UpNR0Y1okLaqZA5VA+wCFZVNCiXO3MXq E/OtL0tpByFJRv/IbrMDnsc1En2PoxbhQbOrKoKwJbAG1D0Yh+iSvae/XwVkJIe1 BH1wuTZT8tZQ3W8UnTcZO9qf30HXlXukOMpbuSlU5XY0tnGWeT58/UaGELx/szFf 8wZ0IuXWrKVOfsFXJGiA+3+0o7J7f8bbzZDArmDPTZmRDJI39DNerzfR4HOWg59K 4cHEKBg7Q/iw+a1o1EdmNQWAL0ZGH/53j1YWCtEEgYfmb+NRCH/2XAa2OVvUrY7I nY7zEHhBp9nPU5bbJiO2Ws0ZL7cF+SIHYW5HjDqjQ0CFs1SNTB10ezNvM70qdJHw glEQ3J2em4vCsUHnkjS5gLFFe8XtxbXQTikKjR7zModGVCF8fCcOAjudWPnLoMJJ GlsG1JFQm7p278wQLEZ1kO/2K80oBmTSKBWon3WXSXStl5KD02sgC9K/H/DIa1VB lZYoTv8UPz7vPrMWJ1JUXuO28V3fe0gEImvAISG+ksjaE7Lm4OIMx8IcO88+4wq4 Oez4jmBUhuh1UDZzpbVY =NcLk -----END PGP SIGNATURE----- --sm4nu43k4a2Rpi4c--