From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Date: Fri, 17 Apr 2020 19:08:54 +0000 Subject: Re: [PATCH 0/8] drm, fbdev: rework dependencies Message-Id: <20200417190854.GI26002@ziepe.ca> List-Id: References: <20200417155553.675905-1-arnd@arndb.de> <20200417171453.GS3456981@phenom.ffwll.local> In-Reply-To: <20200417171453.GS3456981@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Daniel Vetter Cc: linux-fbdev@vger.kernel.org, airlied@linux.ie, dri-devel@lists.freedesktop.org, Andrzej Hajda , Laurent.pinchart@ideasonboard.com, robert.jarzmik@free.fr, marex@denx.de, thellstrom@vmware.com, dsd@laptop.org, jfrederich@gmail.com, masahiroy@kernel.org, Saeed Mahameed , geert@linux-m68k.org, linux-graphics-maintainer@vmware.com, Arnd Bergmann , haojian.zhuang@gmail.com, Nicolas Pitre , linux-renesas-soc@vger.kernel.org, kieran.bingham+renesas@ideasonboard.com, daniel@zonque.org On Fri, Apr 17, 2020 at 07:14:53PM +0200, Daniel Vetter wrote: > On Fri, Apr 17, 2020 at 05:55:45PM +0200, Arnd Bergmann wrote: > > I tried to fix up some dependencies after the sii8620 "imply EXTCON" > > statementn broke, trying a few things but in the backing out a > > change that would completely reverse the LEDS_CLASS selects into > > a 'depends on'. > > > > However, what I got now are multiple changes that remove gratious > > "selects" that lead to circular dependencies for sii8620 and others: > > > > - Anything doing "select FB" is now gone, or becomes "depends on FB", > > > > - DDC support depends on I2C instead of selecting it > > > > - backlight class device support is never selected by framebuffer > > drivers but has proper dependencies > > > > I have done thousands of randconfig build tests on this, but no > > runtime tests. > > > > Some of the 'depends on FOO || !FOO' statements could be simplified > > into a new 'uses FOO' syntax based on a patch from Saeed Mahameed, > > but I would for the moment treat that as a cleanup that can be done > > later. > > > > If we can agree on these changes, maybe someone can merge them > > through the drm-misc tree. > > > > Please review > > Biggest concern I have is that usability of make menuconfig is horrible, > and it's very hard to find options that are hidden by depends on. You can > use the search interface, if you happen to know the option. > > Once you've surmounted that bar, the next one is trying to find what > exactly you need to enable. Which again means endless of recursive > screaming at Kconfig files, since make menuconfig doesn't help you at all. +1 on this. But this is a general kconfig problem, and not unique to DRM, I've done this screaming for many different things now.. eg to turn on every single RDMA driver. I hackily delt with it by creating this rather insane script based on the python kconfiglib to try and sort things out mostly automatically: https://github.com/jgunthorpe/Kernel-Maintainer-Tools/blob/master/gj_tools/cmd_kconfig.py It would be great if menuconfig had a key to say 'hey, really, turn this on and everything it depends on, recursively' Jason