Re: [PATCH] save and restore etm state across core OFF modes

Alexander Shishkin
2010-01-12T21:48:33Z

On Tue, Jan 12, 2010 at 01:04:04 -0800, Tony Lindgren wrote:
> * Nishanth Menon <nm@ti.com> [100112 09:31]:
> > Alexander Shishkin had written, on 01/12/2010 11:30 AM, the following:
> > >On Tue, Jan 12, 2010 at 11:13:13 -0600, Nishanth Menon wrote:
> > >>Alexander Shishkin had written, on 01/12/2010 11:04 AM, the following:
> >
> > >>>diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
> > >>>index 69521be..0a5ec86 100644
> > >>>--- a/arch/arm/mach-omap2/sleep34xx.S
> > >>>+++ b/arch/arm/mach-omap2/sleep34xx.S
> > [...]
> > >>> /* Store current cpsr*/
> > >>> mrs r2, cpsr
> > >>> stmia r8!, {r2}
> > >>>@@ -520,6 +616,7 @@ clean_caches:
> > >>> cmp r9, #1 /* Check whether L2 inval is required or not*/
> > >>> bne skip_l2_inval
> > >>>clean_l2:
> > >>>+#if 0
> > >>my aversion to #if 0 kicks in here :(.. do we have an alternative
> > >>like using the CONFIG_ENABLE_OFF_MODE_JTAG_ETM_DEBUG or something
> > >>else?
> > >
> > >Fair enough. I could replace it with "#if !defined(...)" as the first
> > >thing that comes to mind. This way it will only take disabling the
> > >config option to catch any possible regressions in between. Does this
> > >sound reasonable?
> > sounds ok to me.. unless folks have ideas coz of clean_l2 label..
> > more comments might be useful before a rev2 of the patch..
>
> The best solution would be to be able to toggle this via sysfs or
> debugfs by swapping the sram code for idle loop when JTAG support
> is needed.

Well, if you say, compile the ETM driver in, this will be needed most of
the time.

Regards,
--
Alex