On Sat, Oct 10, 2015 at 01:42:47AM +0100, Måns Rullgård wrote: > Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> writes: > > > On Sat, Oct 10, 2015 at 12:48:22AM +0100, Måns Rullgård wrote: > >> Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> writes: > >> > >> > On Fri, Oct 09, 2015 at 10:57:35PM +0100, Mans Rullgard wrote: > >> >> This passes a data pointer specified in the sched_clock_register() > >> >> call to the read callback allowing simpler implementations thereof. > >> >> > >> >> In this patch, existing uses of this interface are simply updated > >> >> with a null pointer. > >> > > >> > This is a bad description. It tells us what the patch is doing, > >> > (which we can see by reading the patch) but not _why_. Please include > >> > information on why the change is necessary - describe what you are > >> > trying to achieve. > >> > >> Currently most of the callbacks use a global variable to store the > >> address of a counter register. This has several downsides: > >> > >> - Loading the address of a global variable can be more expensive than > >> keeping a pointer next to the function pointer. > >> > >> - It makes it impossible to have multiple instances of a driver call > >> sched_clock_register() since the caller can't know which clock will > >> win in the end. > >> > >> - Many of the existing callbacks are practically identical and could be > >> replaced with a common generic function if it had a pointer argument. > >> > >> If I've missed something that makes this a stupid idea, please tell. > > > > So my next question is whether you intend to pass an iomem pointer > > through this, or a some kind of structure, or both. It matters, > > because iomem pointers have a __iomem attribute to keep sparse > > happy. Having to force that attribute on and off pointers is frowned > > upon, as it defeats the purpose of the sparse static checker. > > So this is an instance where tools like sparse get in the way of doing > the simplest, most efficient, and obviously correct thing. Who wins in > such cases? In that case, NAK on the patch. I don't have time for your stupid games. -- FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
