The following commit has been merged in the linux branch: commit b427f92f8cfca2787c18a77bef15cc8b13341774 Author: Kevin Hilman khilman@deeprootsystems.com Date: Thu Oct 22 14:48:13 2009 -0700
omap3: PM: enable UART3 module wakeups
UART3 is in the PER powerdomain. If PER goes idle/inactive independently of CORE, for UART3 to wakeup it must have its wakeup enable bits setup in PM_WKEN_PER. This patch enables these bits.
The reason it works when PER and CORE work together is because when CORE goes inactive/retention, the IOPAD wakeups are enabled and trigger UART3 wakeup.
Without this patch, when the UART inactivity timer fires for UART3, its clocks are disabled and it's unable to wakeup so will be unusable until PER is awoken by another source.
Another way of testing is by keeping CORE on during suspend but allowing PER to hit retention
# echo 3 > /debug/pm_debug/core_pwrdm/suspend
then enter suspend
# echo mem > /sys/power/state
Without this patch, UART3 will be unable to wakeup the system.
Signed-off-by: Kevin Hilman khilman@deeprootsystems.com Signed-off-by: Tony Lindgren tony@atomide.com
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c index 378c2f6..8946319 100644 --- a/arch/arm/mach-omap2/pm34xx.c +++ b/arch/arm/mach-omap2/pm34xx.c @@ -639,14 +639,15 @@ static void __init prcm_setup_regs(void) prm_write_mod_reg(OMAP3430_IO_EN | OMAP3430_WKUP_EN, OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
- /* Enable GPIO wakeups in PER */ + /* Enable wakeups in PER */ prm_write_mod_reg(OMAP3430_EN_GPIO2 | OMAP3430_EN_GPIO3 | OMAP3430_EN_GPIO4 | OMAP3430_EN_GPIO5 | - OMAP3430_EN_GPIO6, OMAP3430_PER_MOD, PM_WKEN); + OMAP3430_EN_GPIO6 | OMAP3430_EN_UART3, + OMAP3430_PER_MOD, PM_WKEN); /* and allow them to wake up MPU */ prm_write_mod_reg(OMAP3430_GRPSEL_GPIO2 | OMAP3430_EN_GPIO3 | OMAP3430_GRPSEL_GPIO4 | OMAP3430_EN_GPIO5 | - OMAP3430_GRPSEL_GPIO6, + OMAP3430_GRPSEL_GPIO6 | OMAP3430_EN_UART3, OMAP3430_PER_MOD, OMAP3430_PM_MPUGRPSEL);
/* Don't attach IVA interrupts */