Re: [PATCH] input: st1232: Add IRQF_NO_SUSPEND flag

[Magnus Damm <magnus.damm@gmail.com>]

Hi Bastian,

On Tue, Feb 19, 2013 at 12:48 AM, Bastian Hecht <hechtb@gmail.com> wrote:
> Hi Magnus,
>
> 2013/2/14 Magnus Damm <magnus.damm@gmail.com>:
>> Hi Bastian,
>>
>> On Fri, Feb 15, 2013 at 2:32 AM, Bastian Hecht <hechtb@gmail.com> wrote:
>>> When registering the interrupt handler we add the IRQF_NO_SUSPEND flag
>>> to save the IRQ line from being disabled during suspension. This way we
>>> keep the ability to use the device as a wakeup source.
>>>
>>> Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
>>> ---
>>>  drivers/input/touchscreen/st1232.c |    2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
>>> index d9d05e2..4f37199 100644
>>> --- a/drivers/input/touchscreen/st1232.c
>>> +++ b/drivers/input/touchscreen/st1232.c
>>> @@ -180,7 +180,7 @@ static int st1232_ts_probe(struct i2c_client *client,
>>>         input_set_abs_params(input_dev, ABS_MT_POSITION_Y, MIN_Y, MAX_Y, 0, 0);
>>>
>>>         error = request_threaded_irq(client->irq, NULL, st1232_ts_irq_handler,
>>> -                                    IRQF_ONESHOT, client->name, ts);
>>> +                       IRQF_ONESHOT | IRQF_NO_SUSPEND, client->name, ts);
>>
>> Are you sure this is the correct way to handle this? Which platform
>> have you tested this on? How about other boards?
>>
>> Usually wake up handling is dealt with separately from interrupts.
>> Looks like something is missing in your interrupt controller code.
>
> I've got 2 different patterns happening on the KZM9G and the Armadillo800EVA.
>
> Armadillo:
> I provoke a fail by using the touchscreen while suspending that
> triggers the first "intc disable 10 10" (see below). The suspend code
> disables all(?) IRQ lines and after
> "PM: noirq suspend of devices complete after 4901.016 msecs"
> the wakeup sources get reenabled. In fact I'm unsure if the IRQ line
> 10 gets reenabled by the generic IRQ handling code when reenabling the
> line after handling it or if it is done by code that sets up the
> wakeup sources. IRQ 14 is a GPIO button that is marked as a wakeup
> source in the board code:
> GPIO_KEY(KEY_POWER,     GPIO_PORT99,    "SW3", .wakeup = 1),

Thanks for giving more details. You write that you are unsure about
some things, would it be possible for you to track down those things
so we know for sure?

> Now the strange thing here is that even after enabling IRQ line 10
> ("intc write8: addr e0804064, h 2034a25, data 20" is the correct write
> to unmask it) the touchscreen stays dead and I can't wake using it.
> Even if I wake it using the GPIO key the st1232 stays dead and I don't
> get any more interrupts from it.

The sleep mode you are using is a plan "WFI" at this point, right? If
you are controlling power domains then you may have to involve the
SYSC hardware depending on which power domains you turn off.

> When I suspend while not using the touchscreen I get the same sequence
> without the inital "intc disable 10 10" and no i2c timeout happens and
> I am able to wake from the st1232.

Is it possible that the IRQ of the st1232 is in level trigger mode,
and when you use the touch screen the IRQ gets asserted and remains
asserted? If you read out the registers of the st1232 can you see if
the IRQ is asserted?

Another alternative is that the INTC code is masking with priority
instead of bitmap and something is lacking. It sounds more like an
asserted interrupt though.

Yet another option is that some piece of code is missing to
acknowledge interrupts on resume.

> Here my log:
> PM: Syncing filesystems ... done.
> Freezing user space processes ... (elapsed 0.02 seconds) done.
> Freezing remaining freezable tasks ... (elapsed 0.02 seconds) done.
> intc disable 10 10
> intc write8: addr e0804044, h 2034a25, data 20
> PM: suspend of devices complete after 243.854 msecs
> PM: late suspend of devices complete after 0.327 msecs
> intc disable 10 10
> intc write8: addr e0804044, h 2034a25, data 20
> intc disable 12 12
> intc write8: addr e0804044, h 2034a23, data 8
> intc disable 13 13
> intc write8: addr e0804044, h 2034a22, data 4
> intc disable 14 14
> intc write8: addr e0804044, h 2034a21, data 2
> intc disable 15 15
> intc write8: addr e0804044, h 2034a20, data 1
> intc disable 44 44
> intc write8: addr e69400ac, h 16174a24, data 10
> intc disable 45 45
> intc write8: addr e69400ac, h 16174a25, data 20
> intc disable 46 46
> intc write8: addr e69400ac, h 16174a26, data 40
> intc disable 47 47
> intc write8: addr e69400ac, h 16174a27, data 80
> intc disable 168 168
> intc write8: addr e6950090, h 20214a27, data 80
> intc disable 178 178
> intc write8: addr e6950094, h 22234a25, data 20
> intc disable 444 444
> intc write8: addr e0806190, h 6074a20, data 1
> intc disable 512 512
> intc write8: addr e08061ac, h e0f4a24, data 10
> intc disable 513 513
> intc write8: addr e08061ac, h e0f4a25, data 20
> intc disable 514 514
> intc write8: addr e08061ac, h e0f4a26, data 40
> intc disable 515 515
> intc write8: addr e08061ac, h e0f4a27, data 80
> intc disable 588 588
> intc write8: addr e0808190, h 10114a23, data 8
> i2c-sh_mobile i2c-sh_mobile.0: Transfer request timed out
> i2c-sh_mobile i2c-sh_mobile.0: Polling timed out
> PM: noirq suspend of devices complete after 4977.712 msecs
> intc enable 10 10
> intc write8: addr e0804064, h 2034a25, data 20
> intc enable 14 14
> intc write8: addr e0804064, h 2034a21, data 2

That's exciting. =)

For other people to help you it would be good if you could share more
information, like for instance which git branch you are working
against and also if you have done any modifications yourself.

> KZM9G:
>
> Here even if I don't produce IRQs from the st1232 I can't wake without
> the patch. The IRQ gets disabled as in the log above but there is no
> reenabling at all. So my patch stops disabling the IRQ line in the
> first place and we are able to use it as a wakeup source.
>
> # echo mem >/sys/power/state
> PM: Syncing filesystems ... done.
> PM: Preparing system for mem sleep
> Freezing user space processes ... (elapsed 0.02 seconds) done.
> Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
> PM: Entering mem sleep
> PM: suspend of devices complete after 3.417 msecs
> PM: late suspend of devices complete after 0.244 msecs
> intc disable 568 568
> intc write8: addr df00a044, h 2034a27, data 80
> intc disable 444 444
> intc write8: addr df004190, h 6074a20, data 1
> intc disable 947 947
> intc write8: addr df00a048, h 4054a24, data 10
> intc disable 954 954
> intc write8: addr df00a04c, h 6074a25, data 20
> PM: noirq suspend of devices complete after 25.146 msecs
> Disabling non-boot CPUs ...
> CPU1: shutdown
>
> No wakeup possible here. Btw there is 1 more thing that confuses me:
> The touchscreen IRQ line is 424 in /proc/interrupts: 424:         34
>        0  INTCA-GIC-level     st1232-ts
> but when using it I get
> intc disable 568 568
> intc write8: addr df00a044, h 2034a27, data 80
> intc enable 568 568
> intc write8: addr df00a064, h 2034a27, data 80
>
> But IRQ line 568 doesn't exist at all in /proc/interrupts. Can you explain that?

I suppose you will have to decode how the different IRQs are mapped in
intc-sh73a0.c.

One of the key differences between r8a7740 and sh73a0 is that r8a7740
is using INTC only and sh73a0 is making use of the GIC. So for KZM9G
you have to take the GIC into consideration. If you have not dived
into that code yet then now is a good time.

Also, regarding the external IRQ pins on sh73a0, perhaps the function
sh73a0_set_wake() needs to be updated?

> So you are probably right, there is something phony in the interrupt
> controller code. And probably in 2 different spots.

Why don't you focus on tracking down the r8a7740 external IRQ issue?
Try to figure out if the IRQ is stuck asserted.

As for sh73a0 External IRQ pins, I am about to post a v2 of my INTC
external IRQ pin driver and will also include some platform data for
sh73a0. You may want to give that a try.

A good conclusion here is probably that this patch adding the
IRQF_NO_SUSPEND flag is not the correct solution to these problems.
You may have to do some modification about the drivers, but I believe
they are likely to be rather fine as-is. In the case of the st1232
driver it has been used on the sh7372 mackerel board and there we are
(at least have been) able to use Suspend-to-RAM in various ways.

Thanks,

/ magnus