From mboxrd@z Thu Jan 1 00:00:00 1970 From: Crestez Dan Leonard Subject: Re: [PATCH v2 6/7] iio: inv_mpu6050: Reformat sample for active scan mask Date: Mon, 30 May 2016 16:44:41 +0300 Message-ID: <49c4a235-29fd-aa55-d9d2-8ead5cefd737@intel.com> References: <7df4b331d35e3e6a19d13ccbcb5d12f0347b660c.1463582011.git.leonard.crestez@intel.com> <14d4a757-f60a-40c0-03b4-c36d1b22d30e@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <14d4a757-f60a-40c0-03b4-c36d1b22d30e-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jonathan Cameron , linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Daniel Baluta , Ge Gao , Peter Rosin , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wolfram Sang , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala List-Id: devicetree@vger.kernel.org On 05/29/2016 06:47 PM, Jonathan Cameron wrote: > On 18/05/16 16:00, Crestez Dan Leonard wrote: >> Right now it is possible to only enable some of the x/y/z channels, for >> example you can enable accel_z without x or y but if you actually do >> that what you get is actually only the x channel. >> >> Fix this by reformatting the hardware sample to only include the >> requested channels. > As it stands here there is no benefit in doing this over using the core > demux. In fact it's considerably less efficient (fair enough that you > are keeping it simple in the first instance). > The patch description should make that clear. Why is it less efficient? All it really does is a bunch of memcpy. > I'd definitely like to see simple extension of that option to handle > a callback to get the nearest scanmask that is possible (as an alternative > to the static scan_masks_available list.) > > This only gets interesting if we are dealing with the unaligned case and for > these parts that only kicks in I think if the slave devices have say 3 bytes in > their data type. But I want to deal with the unaligned case because it's better than introducing odd validations on slave channels. If I added an extension to get the nearest scanmask I would have to remove it in PATCH 7. -- Regards, Leonard