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: Tue, 31 May 2016 11:56:51 +0300 Message-ID: <3169df0b-78d8-a35c-bd31-f2d4e7e17bde@intel.com> References: <7df4b331d35e3e6a19d13ccbcb5d12f0347b660c.1463582011.git.leonard.crestez@intel.com> <14d4a757-f60a-40c0-03b4-c36d1b22d30e@kernel.org> <49c4a235-29fd-aa55-d9d2-8ead5cefd737@intel.com> <4EB54DBB-A77A-4BC5-8960-5CE9EB1B5DF2@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4EB54DBB-A77A-4BC5-8960-5CE9EB1B5DF2@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Jonathan Cameron , linux-iio@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Daniel Baluta , Ge Gao , Peter Rosin , linux-i2c@vger.kernel.org, Wolfram Sang , devicetree@vger.kernel.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala List-Id: devicetree@vger.kernel.org On 05/31/2016 12:42 AM, Jonathan Cameron wrote: > On 30 May 2016 14:44:41 BST, Crestez Dan Leonard wrote: >> 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. > > Not doing agglomeration of neighbouring copies (iirc) not git either set of code to > hand! You're right about that. But the total data rate is still very low. >>> 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. > Hmm I must have misread that. Though you were only supporting 16 bit channels > for aux sensors. That was in a previous version, I dropped that limitation now. > Then for now can we give this a slightly less generic name. I am not happy > enough that we want this in the core 'yet'. > Easy to rename later if it makes sense. Ok, I will rename these functions to start with inv_mpu_* instead of iio_*. In theory it would be interesting to refactor the iio demuxing code to support this but then this patch serios would grow even more complicated. -- Regards, Leonard