[PATCH 0/1] dying serial console in PM branch

[PATCH 0/1] dying serial console in PM branch

[Kevin Hilman]

This patch fixes the problems in the PM branch where the serial
console on UART3 was not able to wakeup after the inactivity timer.

This fix has been pushed to the PM branch already, but should also
be queued as a fix upstream.

Tony, this is available in my pm-upstream/pm-fixes-32 branch based at
v2.6.32-rc5.  I shouldn't have any more PM fixes coming for 2.6.32.

Kevin Hilman (1):
  OMAP3: PM: enable UART3 module wakeups

 arch/arm/mach-omap2/pm34xx.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

[PATCH 1/1] OMAP3: PM: enable UART3 module wakeups

[Kevin Hilman]

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>
---
 arch/arm/mach-omap2/pm34xx.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

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 */
-- 
1.6.4.3

Re: [PATCH 0/1] dying serial console in PM branch

[Tony Lindgren]

* Kevin Hilman <khilman@deeprootsystems.com> [091019 15:14]:
> This patch fixes the problems in the PM branch where the serial
> console on UART3 was not able to wakeup after the inactivity timer.
> 
> This fix has been pushed to the PM branch already, but should also
> be queued as a fix upstream.

OK, good to hear you found the problem!
 
> Tony, this is available in my pm-upstream/pm-fixes-32 branch based at
> v2.6.32-rc5.  I shouldn't have any more PM fixes coming for 2.6.32.

Thanks, since it's just one patch, I'll apply it into my omap-fixes
from the patchwork.k.o for easier handling.

Regards,

Tony

> 
> Kevin Hilman (1):
>   OMAP3: PM: enable UART3 module wakeups
> 
>  arch/arm/mach-omap2/pm34xx.c |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
> 
> --
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[APPLIED] [PATCH 1/1] OMAP3: PM: enable UART3 module wakeups

[Tony Lindgren]

This patch has been applied to the linux-omap
by youw fwiendly patch wobot.

Branch in linux-omap: omap-fixes

Initial commit ID (Likely to change): 4d9e7efaf9e87613101068900d6f57d5bea6f129

PatchWorks
http://patchwork.kernel.org/patch/54849/

Git (Likely to change, and takes a while to get mirrored)
http://git.kernel.org/?p=linux/kernel/git/tmlind/linux-omap-2.6.git;a=commit;h=4d9e7efaf9e87613101068900d6f57d5bea6f129