Re: [PATCH 2/2] Input: omap-keypad: Fix idle configration to not block SoC idle states

From: Dmitry Torokhov
Date: Tue Dec 04 2018 - 14:15:16 EST


On December 4, 2018 11:09:32 AM PST, Tony Lindgren <tony@xxxxxxxxxxx> wrote:
>Hi,
>
>* Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> [181204 04:00]:
>> Hi Tony,
>>
>> On Mon, Dec 03, 2018 at 03:12:51PM -0800, Tony Lindgren wrote:
>> >
>> > With PM enabled, I noticed that pressing a key on the droid4
>keyboard will
>> > block deeper idle states for the SoC. Looks like we can fix this by
>> > managing the idle register to gether with the interrupt similar to
>what
>> > we already do for the GPIO controller.
>>
>> Can you show me where exactly we are doing this? I can't seem to find
>> the matching code.
>
>With your change it now becomes the fix, and we're just missing the
>clearing of the OMAP4_KBD_WAKEUPENABLE register in omap4_keypad_close.
>
>Does the following minimal version with updated comments make
>more sense now?

Awesome, thank you Tony.

>
>Regards,
>
>Tony
>
>8< --------------
>From tony Mon Sep 17 00:00:00 2001
>From: Tony Lindgren <tony@xxxxxxxxxxx>
>Date: Tue, 4 Dec 2018 11:07:56 -0800
>Subject: [PATCH] Input: omap-keypad: Fix idle configration to not block
> SoC idle states
>
>With PM enabled, I noticed that pressing a key on the droid4 keyboard
>will
>block deeper idle states for the SoC. Let's fix this by using
>IRQF_ONESHOT
>and stop constantly toggling the device OMAP4_KBD_IRQENABLE register as
>suggested by Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>.
>
>From the hardware point of view, looks like we need to manage the
>registers
>for OMAP4_KBD_IRQENABLE and OMAP4_KBD_WAKEUPENABLE together to avoid
>blocking deeper SoC idle states. And with toggling of
>OMAP4_KBD_IRQENABLE
>register now gone with IRQF_ONESHOT, also the SoC idle state problem is
>gone during runtime. We still also need to clear OMAP4_KBD_WAKEUPENABLE
>in
>omap4_keypad_close() though to pair it with omap4_keypad_open() to
>prevent
>blocking deeper SoC idle states after rmmod omap4-keypad.
>
>Cc: Axel Haslam <axelhaslam@xxxxxx>
>Cc: Illia Smyrnov <illia.smyrnov@xxxxxx>
>Cc: Marcel Partap <mpartap@xxxxxxx>
>Cc: Merlijn Wajer <merlijn@xxxxxxxxxx>
>Cc: Michael Scott <hashcode0f@xxxxxxxxx>
>Cc: NeKit <nekit1000@xxxxxxxxx>
>Cc: Pavel Machek <pavel@xxxxxx>
>Cc: Sebastian Reichel <sre@xxxxxxxxxx>
>Reported-by: Pavel Machek <pavel@xxxxxx>
>Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
>---
> drivers/input/keyboard/omap4-keypad.c | 16 ++++------------
> 1 file changed, 4 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/input/keyboard/omap4-keypad.c
>b/drivers/input/keyboard/omap4-keypad.c
>--- a/drivers/input/keyboard/omap4-keypad.c
>+++ b/drivers/input/keyboard/omap4-keypad.c
>@@ -126,12 +126,8 @@ static irqreturn_t omap4_keypad_irq_handler(int
>irq, void *dev_id)
> {
> struct omap4_keypad *keypad_data = dev_id;
>
>- if (kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS)) {
>- /* Disable interrupts */
>- kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
>- OMAP4_VAL_IRQDISABLE);
>+ if (kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS))
> return IRQ_WAKE_THREAD;
>- }
>
> return IRQ_NONE;
> }
>@@ -173,11 +169,6 @@ static irqreturn_t omap4_keypad_irq_thread_fn(int
>irq, void *dev_id)
> kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
> kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
>
>- /* enable interrupts */
>- kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
>- OMAP4_DEF_IRQENABLE_EVENTEN |
>- OMAP4_DEF_IRQENABLE_LONGKEY);
>-
> return IRQ_HANDLED;
> }
>
>@@ -214,9 +205,10 @@ static void omap4_keypad_close(struct input_dev
>*input)
>
> disable_irq(keypad_data->irq);
>
>- /* Disable interrupts */
>+ /* Disable interrupts and wake-up events */
> kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
> OMAP4_VAL_IRQDISABLE);
>+ kbd_writel(keypad_data, OMAP4_KBD_WAKEUPENABLE, 0);
>
> /* clear pending interrupts */
> kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
>@@ -365,7 +357,7 @@ static int omap4_keypad_probe(struct
>platform_device *pdev)
> }
>
> error = request_threaded_irq(keypad_data->irq,
>omap4_keypad_irq_handler,
>- omap4_keypad_irq_thread_fn, 0,
>+ omap4_keypad_irq_thread_fn, IRQF_ONESHOT,
> "omap4-keypad", keypad_data);
> if (error) {
> dev_err(&pdev->dev, "failed to register interrupt\n");



--
Dmitry