From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH v10 2/2] tty/serial: Add Spreadtrum sc9836-uart driver support Date: Fri, 30 Jan 2015 15:49:26 +0000 Message-ID: <20150130154926.GN26493@n2100.arm.linux.org.uk> References: <1422443324-25082-1-git-send-email-chunyan.zhang@spreadtrum.com> <1422443324-25082-3-git-send-email-chunyan.zhang@spreadtrum.com> <54CA5128.8050500@gmail.com> <54CA568E.6080306@hurleysoftware.com> <20150129160553.GC26493@n2100.arm.linux.org.uk> <20150130101838.GC16744@ulmo> <54CB72F7.8060706@hurleysoftware.com> <20150130140854.GJ26493@n2100.arm.linux.org.uk> <54CBA426.7050900@hurleysoftware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <54CBA426.7050900-WaGBZJeGNqdsbIuE7sb01tBPR1lH4CV8@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter Hurley Cc: Thierry Reding , Varka Bhadram , Chunyan Zhang , gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, gnomes-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org, heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org, andrew-g2DYL2Zd6BY@public.gmane.org, jslaby-AlSwsSmVLrQ@public.gmane.org, lanqing.liu-lxIno14LUO0EEoCn2XhGlw@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, zhang.lyra-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, zhizhou.zhang-lxIno14LUO0EEoCn2XhGlw@public.gmane.org, geng.ren-lxIno14LUO0EEoCn2XhGlw@public.gmane.org, antonynpavlov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, orsonzhai-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, florian.vaussard-p8DiymsW2f8@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, hytszk-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, wei.qiao-lxIno14LUO0EEoCn2XhGlw@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org List-Id: linux-api@vger.kernel.org On Fri, Jan 30, 2015 at 10:32:54AM -0500, Peter Hurley wrote: > Before you say consistency, I think you should look at the stats below. > IOW, if you want to change the error code return from probe() for > consistency's sake, a tree-wide patch would be the appropriate way. Now look outside the serial driver sub-tree. There are 1234 instances of platform_get_resource(, IORESOURCE_MEM, ) in the drivers/ sub-tree, with 700 instances of devm_ioremap_resource() being used there. Of the devm_ioremap_resource() instances: - 555 use platform_get_resource() in the preceding two lines - which is not enough to do anything but rely on the -EINVAL return value. - 16 mention ENODEV in the preceding three lines. There are 132 which use platform_get_resource() and return ENODEV within the following three lines (which may intersect with the above 16 number) and 88 which use EINVAL. So, there are in total 643 instances where a missing resource returns EINVAL, and between 132 and 148 instances which return ENODEV. Yes, 643 + 148 isn't 1234, but I'm not going to read through all 1234 locations just for the sake of this thread. What's clear though is that more than 50% of sites using platform_get_resource(, IORESOURCE_MEM, ) return EINVAL for the lack of a resource. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.