On Mon, Dec 05, 2011 at 12:40:16PM -0500, Nicolas Pitre wrote: > On Mon, 5 Dec 2011, Dave Martin wrote: > > On Sat, Dec 03, 2011 at 10:12:53AM +1100, Benjamin Herrenschmidt wrote: > > > On Fri, 2011-12-02 at 11:28 -0800, Linus Torvalds wrote: > > > > Don't *change* NO_IRQ to zero (that whole #define is broken - leave it > > > > around as a marker of brokenness), just start removing it from all the > > > > ARM drivers that use the OF infrastructure. Which is presumably not > > > > all that many yet. > > > > > > > > So whenever you find breakage, the fix now is to just remove NO_IRQ > > > > tests, and replace them with "!irq". > > > > > > > Russell, do you know whether it would make sense to set a timeline for > > removing NO_IRQ from ARM platforms and migrating to 0 for the no-interrupt > > case? I'm assuming that this mainly involves migrating existing hard-wired > > code that deals with interrupt numbers to use irq domains. > > How many drivers do use IRQ #0 to start with? We might discover that in > practice there is only a very few cases where this is an issue if 0 > would mean no IRQ. The total number of files referring to NO_IRQ is not that huge: arch/arm/ 188 matches in 39 files drivers/ 174 matches in 84 files Unfortunately, NO_IRQ is often not spelled "NO_IRQ". It looks like the assumption "irq < 0 === no irq" may be quite a lot more widespread than "NO_IRQ === no irq". Since there's no specific thing we can grep for (and simply due to volume) finding all such instances may be quite a bit harder. For example, git grep 'irq.*\(>=\|<[^=]\) *0' gives drivers/ 435 matches in 314 files arch/arm/ 18 matches in 15 files A few examples: drivers/input/mouse/pxa930_trkball.c: if (irq < 0) { drivers/input/keyboard/tegra-kbc.c: if (irq < 0) { drivers/crypto/omap-sham.c: if (dd->irq >= 0) ...etc., etc., although there are probably a fair number of false positives here. whereas git grep 'irq.*\(<\|>\|<=\|>=\|==\|!=\) \+-1' gives drivers/ 68 matches in 28 files arch/arm/ 18 matches in 15 files Examples: ...and that's just the code which is C and is also kind enough to put irq numbers in variables with names containing "irq". It also doesn't catch people initialising variables or struct/array members to -1, unadorned "-1" arguments to functions and so on... though those are likely to appear in mostly the same files matching the above expressions, it won't be an exact 1:1 correspondence. Cheers ---Dave -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html