From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH v12 01/11] bitops: Introduce the for_each_set_clump8 macro Date: Tue, 26 Mar 2019 12:19:33 +0200 Message-ID: <20190326101933.GW9224@smile.fi.intel.com> References: <9afc30a574ce3e6a86b51dd522146a1d2156dedd.1553494625.git.vilhelm.gray@gmail.com> <20190325093854.jzkkwaksxi7zvtrg@wunner.de> <20190326031422.GB3356@icarus> <20190326094345.v7l7xjvfs2scbvbv@wunner.de> <20190326100743.GA10005@icarus> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190326100743.GA10005@icarus> Sender: linux-kernel-owner@vger.kernel.org To: William Breathitt Gray Cc: Lukas Wunner , linus.walleij@linaro.org, bgolaszewski@baylibre.com, akpm@linux-foundation.org, linux-gpio@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux@rasmusvillemoes.dk, yamada.masahiro@socionext.com, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, geert@linux-m68k.org, preid@electromag.com.au, Arnd Bergmann List-Id: linux-gpio@vger.kernel.org On Tue, Mar 26, 2019 at 07:08:18PM +0900, William Breathitt Gray wrote: > On Tue, Mar 26, 2019 at 10:43:45AM +0100, Lukas Wunner wrote: > > On Tue, Mar 26, 2019 at 12:14:22PM +0900, William Breathitt Gray wrote: > > Why is it so complicated, does it allow passing in a start value > > that's not a multiple of 8? Do you really need that? I imagine > > a simplification is possible if that assumption can be made (and > > is spelled out in the kerneldoc). > > That's a good point. Originally, I had envisioned the possibility of > calling bitmap_get_value8/bitmap_set_value8 at odd start offsets; this > would open up the possibility of a clump landing as a split between 2 > words, thus requiring this complicated case handling code. However, I'm > not sure how often users would need this case; none of the drivers right > now require clumps at odd offsets. > > Andy, would you have any objection to restricting the start offset > values for bitmap_get_value8/bitmap_set_value8 to multiples of 8? That > would prevent the split word case, and thus allow the implementation for > those functions to be a lot simpler. No, I have no objection. -- With Best Regards, Andy Shevchenko