Linus Torvalds 23c35f48f5 pinctrl: remove include file from <linux/device.h> ... When pulling the recent pinctrl merge, I was surprised by how a pinctrl-only pull request ended up rebuilding basically the whole kernel. The reason for that ended up being that <linux/device.h> included <linux/pinctrl/devinfo.h>, so any change to that file ended up causing pretty much every driver out there to be rebuilt. The reason for that was because 'struct device' has this in it: #ifdef CONFIG_PINCTRL struct dev_pin_info *pins; #endif but we already avoid header includes for these kinds of things in that header file, preferring to just use a forward-declaration of the structure instead. Exactly to avoid this kind of header dependency. Since some drivers seem to expect that <linux/pinctrl/devinfo.h> header to come in automatically, move the include to <linux/pinctrl/pinctrl.h> instead. It might be better to just make the includes more targeted, but I'm not going to review every driver. It would definitely be good to have a tool for finding and minimizing header dependencies automatically - or at least help with them. Right now we almost certainly end up having way too many of these things, and it's hard to test every single configuration. FWIW, you can get a sense of the "hotness" of a header file with something like this after doing a full build: find . -name '.*.o.cmd' -print0 | xargs -0 tail --lines=+2 | grep -v 'wildcard ' | tr ' \\' '\n' | sort | uniq -c | sort -n | less -S which isn't exact (there are other things in those '*.o.cmd' than just the dependencies, and the "--lines=+2" only removes the header), but might a useful approximation. With this patch, <linux/pinctrl/devinfo.h> drops to "only" having 833 users in the current x86-64 allmodconfig. In contrast, <linux/device.h> has 14857 build files including it directly or indirectly. Of course, the headers that absolutely _everybody_ includes (things like <linux/types.h> etc) get a score of 23000+. Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2018-02-03 12:10:09 -08:00
..
consumer.h
devinfo.h	pinctrl: Forward declare struct device	2018-01-22 13:31:19 +01:00
machine.h
pinconf-generic.h	gpio: gpiolib: Generalise state persistence beyond sleep	2017-12-02 22:42:34 +01:00
pinconf.h
pinctrl-state.h
pinctrl.h	pinctrl: remove include file from <linux/device.h>	2018-02-03 12:10:09 -08:00
pinmux.h