diff mbox

[3/3] ARM: dts: omap4-sdp: add dynamic pin states for uart3/4

Message ID 51E7AD38.6010108@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Grygorii Strashko July 18, 2013, 8:54 a.m. UTC 
On 07/18/2013 11:09 AM, Tony Lindgren wrote:
> * Grygorii Strashko <grygorii.strashko@ti.com> [130717 09:48]:
>> Hi,
>>
>> On 07/17/2013 06:32 PM, Tony Lindgren wrote:
>>> * Grygorii Strashko <grygorii.strashko@ti.com> [130717 04:49]:
>>>> Add dynamic "active"/"idle" pin states for uart3/4 which will be applied
>>>> when uart3/4 state is switched from active to idle and back by Runtime
>>>> PM or during system suspend.
>>>
>>> This is good for testing code, but should not be merged because
>>> omap4 has the iopad wake-ups available for uarts. So those can
>>> be always enabled.
>>
>> In this case, 2 IRQ will be received per each UART RX event - one from
>> PRCM and from UART - and that's not good from PM perspective (It will
>> affect on CPUIdle and CPUFreq at least).
>
> Oh I see, that's because I accidentally left the debug code enabled
> to make it easier to test the wake-up events without having to
> have working off-idle. The wake flags can be kept on always for
> sure.
>
> The patch below should sort out the issue of getting wake-up interrupts
> during runtime as long as you don't have DEBUG defined.
>
> Regards,
>
> Tony
>
> --- a/drivers/pinctrl/pinctrl-single-omap.c
> +++ b/drivers/pinctrl/pinctrl-single-omap.c
> @@ -140,9 +140,17 @@ static irqreturn_t pcs_omap_handle_irq(int irq, void *data)
>   		if ((val & OMAP_WAKEUP_EVENT_MASK) == OMAP_WAKEUP_EVENT_MASK)
>   			generic_handle_irq(wakeirq);
>   	}
> -
> +#ifdef DEBUG

Don't think it's debug code - IO chain need to be rearmed after each
PRCM IO IRQ - otherwise IO wakeup events may be lost (at least on
OMAP4, OMAP5 requires more complex handling(( ).


> +	/*
> +	 * This enables wake-up interrupts during runtime also
> +	 * causing duplicate interrupts. But it also makes debugging
> +	 * the wake-up events easy as deeper idle states often are
> +	 * not working for new devices while the drivers are being
> +	 * developed.
> +	 */
>   	if (pcso->reconfigure_io_chain)
>   		pcso->reconfigure_io_chain();
> +#endif
>
>   	return IRQ_HANDLED;
>   }
>

I didn't pick up your padconf patches yet -seems i need to be in sync :)

Below the diff I used to verify IO wake up (It follows old IO daisy
chain hanlding models in hwmod before DT):


   *
@@ -144,6 +144,7 @@ static void omap_prcm_irq_handler(unsigned int irq, 
struct irq_desc *desc)
         chip->irq_unmask(&desc->irq_data);

         prcm_irq_setup->ocp_barrier(); /* avoid spurious IRQs */
+       omap44xx_prm_reconfigure_io_chain();
  }


--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Tony Lindgren July 18, 2013, 9:04 a.m. UTC | #1 
* Grygorii Strashko <grygorii.strashko@ti.com> [130718 02:01]:
> On 07/18/2013 11:09 AM, Tony Lindgren wrote:
> 
> Don't think it's debug code - IO chain need to be rearmed after each
> PRCM IO IRQ - otherwise IO wakeup events may be lost (at least on
> OMAP4, OMAP5 requires more complex handling(( ).

Nope, only after the mux register changes. I've verified it on
am3730 with off-idle for both serial and wl12xx.
 
> I didn't pick up your padconf patches yet -seems i need to be in sync :)

Well you need those for proper wake-up event support..

> Below the diff I used to verify IO wake up (It follows old IO daisy
> chain hanlding models in hwmod before DT):

..then these changes not needed with the pinctrl-single changes.

Regards,

Tony
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Grygorii Strashko July 18, 2013, 12:01 p.m. UTC | #2 
Hi Tony,

On 07/18/2013 12:04 PM, Tony Lindgren wrote:
> * Grygorii Strashko <grygorii.strashko@ti.com> [130718 02:01]:
>> On 07/18/2013 11:09 AM, Tony Lindgren wrote:
>>
>> Don't think it's debug code - IO chain need to be rearmed after each
>> PRCM IO IRQ - otherwise IO wakeup events may be lost (at least on
>> OMAP4, OMAP5 requires more complex handling(( ).
>
> Nope, only after the mux register changes. I've verified it on
> am3730 with off-idle for both serial and wl12xx.

Unfortunately, there is a possibility to lose wake up events in case if
IO daisy chain will be rearmed (this will clean up all WAKEUPEVENT bits)
while there is some pending  WAKEUP event present. In this case, 
pcs_omap_handle_irq() will not call generic_handle_irq(wakeirq).

The below patch contains explanation of such kind of issue we've solved
in K3.4
http://git.omapzoom.org/?p=kernel/omap.git;a=commit;h=5ff316db224a2c3c23bfe44261275d520b4f78bb

Currently, in Mainline the same is possible on OMAP4 (which is SMP) if
some Device will be switched to idle and rearm IO chain while there is
pending WAKEUP event form USB for example. So, IO rearming need to be 
delayed until PRCM irq will be served served and PRCM irq handler should 
finally rearm IO daisy chain.


>
>> I didn't pick up your padconf patches yet -seems i need to be in sync :)
>
> Well you need those for proper wake-up event support..
>
>> Below the diff I used to verify IO wake up (It follows old IO daisy
>> chain hanlding models in hwmod before DT):
>
> ..then these changes not needed with the pinctrl-single changes.
>
> Regards,
>
> Tony
>

--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -574,7 +574,7 @@  odbs_exit:

         return ERR_PTR(ret);
  }
-
+#include "prm44xx.h"
  #ifdef CONFIG_PM_RUNTIME
  static int _od_runtime_suspend(struct device *dev)
  {
@@ -586,6 +586,7 @@  static int _od_runtime_suspend(struct device *dev)
         if (!ret) {
                 omap_device_idle(pdev);
                 pinctrl_pm_select_idle_state(dev);
+               omap44xx_prm_reconfigure_io_chain();
         }

         return ret;
@@ -596,6 +597,7 @@  static int _od_runtime_resume(struct device *dev)
         struct platform_device *pdev = to_platform_device(dev);

         pinctrl_pm_select_active_state(dev);
+       omap44xx_prm_reconfigure_io_chain();

         omap_device_enable(pdev);

diff --git a/arch/arm/mach-omap2/prm_common.c 
b/arch/arm/mach-omap2/prm_common.c
index 228b850..5db073a 100644
--- a/arch/arm/mach-omap2/prm_common.c
+++ b/arch/arm/mach-omap2/prm_common.c
@@ -79,7 +79,7 @@  static void omap_prcm_events_filter_priority(unsigned 
long *events,
                 events[i] ^= priority_events[i];
         }
  }
-
+#include "prm44xx.h"
  /*
   * PRCM Interrupt Handler