From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [RFC PATCH] i2c: i2c-mxs: Use DMA mode even for small transfers Date: Mon, 1 Jul 2013 23:05:08 +0200 Message-ID: <201307012305.09050.marex@denx.de> References: <1372711303-17705-1-git-send-email-festevam@gmail.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1372711303-17705-1-git-send-email-festevam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Fabio Estevam Cc: wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org, shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, to-fleischer-zqRNUXuvxA0b1SvskN2V4Q@public.gmane.org, Fabio Estevam List-Id: linux-i2c@vger.kernel.org Dear Fabio Estevam, > From: Fabio Estevam > > Recently we have been seing some reports about PIO mode not working > properly. > > - http://www.spinics.net/lists/linux-i2c/msg11985.html > - http://marc.info/?l=linux-i2c&m=137235593101385&w=2 > - https://lkml.org/lkml/2013/6/24/430 > > Let's use DMA mode even for small transfers. > > Without this patch, i2c reads the incorrect sgtl5000 version on a mx28evk > when touchscreen is enabled: > > [ 5.856270] sgtl5000 0-000a: Device with ID register 0 is not a sgtl5000 > [ 9.877307] sgtl5000 0-000a: ASoC: failed to probe CODEC -19 > [ 9.883528] mxs-sgtl5000 sound.12: ASoC: failed to instantiate card -19 > [ 9.892955] mxs-sgtl5000 sound.12: snd_soc_register_card failed (-19) > > Signed-off-by: Fabio Estevam Can you possibly just disable the PIO for now so the code doesn't need to be re- introduced once fixed? Best regards, Marek Vasut