On Wed, 2012-05-16 at 17:31 -0700, Kevin Hilman wrote: > Tero Kristo <t-kristo@xxxxxx> writes: > > > If AUX_CORE_BOOT0 does not indicate wakeup request for cpu1, put it back > > to off. > > Why is it waking up then? (I know the answer, but will forget. The > changelog serves as my long-term memory.) Will add comment. (Both cpus will wake-up after device-off reset.) > > > This is needed during wakeup from device off to prevent cpu1 > > from being stuck indefinitely in the wakeup loop > > Why does it get stuck? Related to the above, if the AUX_CORE_BOOT0 is not set, the code will wait for it indefinitely in busy loop. > > > and also to prevent wakeup problem on GP chips with device off mode. > > What wakeup problem? This is apparently related to the GIC restore issue addressed with patch 3/8 of the core-ret set (workaround for the ROM bug because of CA9 r2pX gic register change), the interrupts get disabled. Maybe Santosh has some comments on this one. > > > Signed-off-by: Tero Kristo <t-kristo@xxxxxx> > > Assembly code should have some comments to aid comprehension. Will add. > > > > --- > > arch/arm/mach-omap2/omap-headsmp.S | 45 ++++++++++++++++++++++++++++++++--- > > 1 files changed, 41 insertions(+), 4 deletions(-) > > > > diff --git a/arch/arm/mach-omap2/omap-headsmp.S b/arch/arm/mach-omap2/omap-headsmp.S > > index d602555..59c6578 100644 > > --- a/arch/arm/mach-omap2/omap-headsmp.S > > +++ b/arch/arm/mach-omap2/omap-headsmp.S > > @@ -17,8 +17,37 @@ > > > > #include <linux/linkage.h> > > #include <linux/init.h> > > +#include <mach/omap-secure.h> > > +#include "prcm_mpu44xx.h" > > + > > +#define CPU1_PWRSTCTRL (OMAP4430_PRCM_MPU_BASE + OMAP4430_PRCM_MPU_CPU1_INST + \ > > + OMAP4_PM_CPU1_PWRSTCTRL_OFFSET) > > > > __CPUINIT > > + > > +ENTRY(omap_cpu1_off) > > + ldr r12, =CPU1_PWRSTCTRL > > + ldr r0, [r12] > > + and r0, #3 > > + cmp r0, #2 > > + beq exit_cpu1_off > > + > > + mov r0, #0x3 > > + mov r1, #0x0 > > + ldr r12, =OMAP4_MON_SCU_PWR_INDEX > > Help! no comments. > > > + dsb > > + smc #0 > > The DO_SMC in sleep44xx.S suggests there should be another dsb here. Not sure if that is needed here as we have multiple barriers following this, but I'll add it just to be sure. > > > + isb > > + dsb > > + dmb > > + wfi > > + nop > > + nop > > Shoudln't this use omap_do_wfi? Can't, as we don't have stack yet at this point, and omap_do_wfi attempts to push stuff into stack. -Tero > > Kevin > > > +exit_cpu1_off: > > + mov pc, lr > > +ENDPROC(omap_cpu1_off) > > + > > /* > > * OMAP4 specific entry point for secondary CPU to jump from ROM > > * code. This routine also provides a holding flag into which > > @@ -27,32 +56,40 @@ > > * register AuxCoreBoot0. > > */ > > ENTRY(omap_secondary_startup) > > -hold: ldr r12,=0x103 > > + ldr r12,=0x103 > > dsb > > smc #0 @ read from AuxCoreBoot0 > > mov r0, r0, lsr #9 > > mrc p15, 0, r4, c0, c0, 5 > > and r4, r4, #0x0f > > cmp r0, r4 > > - bne hold > > + beq omap_cont_boot > > + > > + bl omap_cpu1_off > > + b omap_secondary_startup > > > > /* > > * we've been released from the wait loop,secondary_stack > > * should now contain the SVC stack for this core > > */ > > +omap_cont_boot: > > b secondary_startup > > ENDPROC(omap_secondary_startup) > > > > ENTRY(omap_secondary_startup_4460) > > -hold_2: ldr r12,=0x103 > > + ldr r12,=0x103 > > dsb > > smc #0 @ read from AuxCoreBoot0 > > mov r0, r0, lsr #9 > > mrc p15, 0, r4, c0, c0, 5 > > and r4, r4, #0x0f > > cmp r0, r4 > > - bne hold_2 > > + beq omap4460_cont_boot > > + > > + bl omap_cpu1_off > > + b omap_secondary_startup_4460 > > > > +omap4460_cont_boot: > > /* > > * GIC distributor control register has changed between > > * CortexA9 r1pX and r2pX. The Control Register secure -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
