linux-kernel - Re: [PATCH 1/1] input: bbnsm_pwrkey: Fix missed key press after suspend

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Message-ID: <ZpG5d1/EsOU4eJEj@lizhi-Precision-Tower-5810>
Date: Fri, 12 Jul 2024 19:17:11 -0400
From: Frank Li <Frank.li@....com>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc: Jacky Bai <ping.bai@....com>, Jason Liu <jason.hui.liu@....com>,
	Peng Fan <peng.fan@....com>,
	"open list:INPUT (KEYBOARD, MOUSE, JOYSTICK, TOUCHSCREEN)..." <linux-input@...r.kernel.org>,
	open list <linux-kernel@...r.kernel.org>, imx@...ts.linux.dev
Subject: Re: [PATCH 1/1] input: bbnsm_pwrkey: Fix missed key press after
 suspend

On Fri, Jul 12, 2024 at 04:04:28PM -0700, Dmitry Torokhov wrote:
> Hi Frank,
> 
> On Fri, Jul 12, 2024 at 06:43:51PM -0400, Frank Li wrote:
> > From: Jacky Bai <ping.bai@....com>
> > 
> > Report input event directly on wakeup to ensure no press event is missed
> > when resuming from suspend.
> > 
> > Signed-off-by: Jacky Bai <ping.bai@....com>
> > Reviewed-by: Peng Fan <peng.fan@....com>
> > Acked-by: Jason Liu <jason.hui.liu@....com>
> > Signed-off-by: Frank Li <Frank.Li@....com>
> > ---
> >  drivers/input/misc/nxp-bbnsm-pwrkey.c | 36 +++++++++++++++++++++++++++
> >  1 file changed, 36 insertions(+)
> > 
> > diff --git a/drivers/input/misc/nxp-bbnsm-pwrkey.c b/drivers/input/misc/nxp-bbnsm-pwrkey.c
> > index 1d99206dd3a8b..9675717ecbdfe 100644
> > --- a/drivers/input/misc/nxp-bbnsm-pwrkey.c
> > +++ b/drivers/input/misc/nxp-bbnsm-pwrkey.c
> > @@ -38,6 +38,7 @@ struct bbnsm_pwrkey {
> >  	int irq;
> >  	int keycode;
> >  	int keystate;  /* 1:pressed */
> > +	bool suspended;
> >  	struct timer_list check_timer;
> >  	struct input_dev *input;
> >  };
> > @@ -70,6 +71,7 @@ static irqreturn_t bbnsm_pwrkey_interrupt(int irq, void *dev_id)
> >  {
> >  	struct platform_device *pdev = dev_id;
> >  	struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
> > +	struct input_dev *input = bbnsm->input;
> >  	u32 event;
> >  
> >  	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);
> > @@ -81,6 +83,16 @@ static irqreturn_t bbnsm_pwrkey_interrupt(int irq, void *dev_id)
> >  	mod_timer(&bbnsm->check_timer,
> >  		   jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
> >  
> > +	/*
> > +	 * Directly report key event after resume to make sure key press
> > +	 * event is never missed.
> > +	 */
> 
> How do you know that wakeup was caused by the key press on this device?
> As far as I can see the driver requests the interrupt as shared, so we
> could end up in bbnsm_pwrkey_interrupt() even if button was not pressed.
> 

In bbnsm_pwrky_interrupt()
{	...
	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);                                           
        	if (!(event & BBNSM_BTN_OFF))                                                               
                	return IRQ_NONE;

	...
}

If wakeup was not caused by pwr key,  irq will do nothing, code will not
reach to here.

Frank

> Thanks.
> 
> -- 
> Dmitry