From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH 02/10] spi: dw-mid: always use duplex transfers when DMA Date: Wed, 24 Sep 2014 09:44:07 +0100 Message-ID: <20140924084407.GF4015@sirena.org.uk> References: <1411060140-2801-1-git-send-email-andriy.shevchenko@linux.intel.com> <1411060140-2801-3-git-send-email-andriy.shevchenko@linux.intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="5tP+uu4DqNOLJklJ" Cc: Vinod Koul , dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andy Shevchenko Return-path: Content-Disposition: inline In-Reply-To: <1411060140-2801-3-git-send-email-andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: --5tP+uu4DqNOLJklJ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Sep 18, 2014 at 08:08:52PM +0300, Andy Shevchenko wrote: > In case of DMA we never got things done until we enable both channels. In case > of receive only or send only mode the user has to provide a dummy buffer. The driver must never impose such requirements on clients, they shouldn't need to know about the quirks of the controller. There's support in the core providing dummy buffers for transmit and receive, you should use that (possibly extending it so the dummies are only provided for DMA). --5tP+uu4DqNOLJklJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBAgAGBQJUIoRWAAoJECTWi3JdVIfQZH4H/idaPNP2clsZIguyvYfWGdMq 1O/rsIdylDSluLD5foEP0shQaLEFzk4fNwAvN++dIVFBUqyDT+Ho3jpG0BTo8HgK 0WBOr0OomMLG5vm2o3ELq2SbYe8LnitdR9P9ED11Nr+n0nc8MfAm4s1wQOZURA44 D9C+xc2HmCJTN/lvF+d8L1Cm+inbr44yZNa9dtE2No/IJ/ww1PdxLbKLaCfiZqBh n8GvcAH46RQ7+7GJCgsmtXon9E604xZV5rlnXNB6WerNlxsFostVACQL2dAJh9RB Q9hS01eKs/KeEAuff9LoE/l39fyZbdRR6Tw/yIm89Oc9CWBZybKNUGMrQFXgci4= =Hwqk -----END PGP SIGNATURE----- --5tP+uu4DqNOLJklJ-- -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html