Messages in this thread | | | Date | Mon, 17 Jun 2013 15:30:21 +0100 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] ARM: mm: cpu_fa526_do_idle: remove WFI |
| |
On Mon, Jun 17, 2013 at 04:14:03PM +0200, Arnd Bergmann wrote: > On Monday 17 June 2013 15:39:20 Jonas Jensen wrote: > > As it was already suggested by Russell King and Arnd Bergmann ( https://lkml.org/lkml/2013/5/16/133 ), moxart and gemini seem to be the only platforms using CPU_FA526, and instead of pointing arm_pm_idle to an empty function from platform code, it makes sense to remove WFI code from the processor specific idle function. > > > > Note: moxart boots and prints to UART without this patch, but input is broken. > > Please make sure you have proper line wraps. Lines in checkin > comments should be no longer than 70 characters normally. > > > Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com> > > Acked-by: Arnd Bergmann <arnd@arndb.de> > > Since this patch is independent from the actual platform support, > it should go through Russell's patch tracker at > http://www.arm.linux.org.uk/developer/patches/
Except... the patch is wrong.
> > arch/arm/mm/proc-fa526.S | 4 +--- > > 1 files changed, 1 insertions(+), 3 deletions(-) > > > > diff --git a/arch/arm/mm/proc-fa526.S b/arch/arm/mm/proc-fa526.S > > index d217e97..85280b1 100644 > > --- a/arch/arm/mm/proc-fa526.S > > +++ b/arch/arm/mm/proc-fa526.S > > @@ -81,9 +81,7 @@ ENDPROC(cpu_fa526_reset) > > */ > > .align 4 > > ENTRY(cpu_fa526_do_idle) > > - mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt > > - mov pc, lr > > - > > + nop
It replaces the WFI and return with a pure nop, so we will fall through to cpu_fa526_dcache_clean_area(). Do we really want to clean a random D cache entry depending on what r0 happened to hold at this point? I think not...
| |