Hi

On Mon, 10 Sep 2012, Jon Hunter wrote:

From: Ming Lei <redacted>

For OMAP4430 there are no dedicate PMU interrupts, however, PMU events can be
routed to via the CTI IRQs. This allows tools such as PERF and OPROFILE to work
on OMAP4430.

The idea is from Woodruff Richard in the disscussion about "Oprofile on
Pandaboard / Omap4" on pandaboard at googlegroups.com.

Ming's original patch was called "arm: omap4: support pmu" [1] and has been
renamed and modified by Jon Hunter. There main differences from the original
patch are ...

1. Instead of only configuring the CTI interrupt once during boot, the
   interrupts are configured everytime the the PMU is used. The reason for this
   is because during power transitions the CTI logic state will be lost and so
   we will need to configure the interrupts everytime they are used. This is
   accomplished by using the PM runtime callbacks which will be called whenever
   the PMU is used.
2. Assign the PMU events to different cross triggering channels. This prevents
   a single PMU event generating interrupts to both CPUs and hence can cause
   spurious interrupts to occur. Reported by Ming [2].

[1] http://marc.info/?l=linux-arm-kernel&m=132227620816504&w=2
[2] http://permalink.gmane.org/gmane.linux.linaro.devel/10532

Spent some time with this one here.  At this point I don't think I can 
queue it.  It's got hardcoded IRQ numbers and address information for the 
CTI, and mixes the CTI and PMU programming.  A few months ago we might 
have gotten away with this, but now it seems best to do this one cleanly.
Probably the CTI control should be moved off into mach-omap2/omap4-cti.c 
or somewhere into drivers/ if possible.  So let's revisit this for 3.8.


- Paul