On Mon, Sep 16, 2019 at 07:45:37AM +0000, Robin Gong wrote:

On 2019/9/13 15:31 robin [off-list ref] wrote:> 

quoted

Hi Dmitry,

On 2019-09-12 22:13, Dmitry Torokhov wrote:

quoted

Hi Robin,

On Wed, Sep 04, 2019 at 06:23:29AM +0000, Robin van der Gracht wrote:

quoted

The first generation i.MX6 processors does not send an interrupt when
the power key is pressed. It sends a power down request interrupt if
the key is released before a hard shutdown (5 second press). This
should allow software to bring down the SoC safely.

For this driver to work as a regular power key with the older SoCs,
we need to send a keypress AND release when we get the power down
request irq.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
---

@@ -67,13 +83,17 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int

irq, void *dev_id)  {
 	struct platform_device *pdev = dev_id;
 	struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
+	unsigned long expire = jiffies;
 	u32 lp_status;

 	pm_wakeup_event(pdata->input->dev.parent, 0);

 	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
-	if (lp_status & SNVS_LPSR_SPO)
-		mod_timer(&pdata->check_timer, jiffies +
msecs_to_jiffies(DEBOUNCE_TIME));
+	if (lp_status & SNVS_LPSR_SPO) {
+		if (pdata->minor_rev > 0)
+			expire = jiffies + msecs_to_jiffies(DEBOUNCE_TIME);
+		mod_timer(&pdata->check_timer, expire);

Why do we even need to fire the timer in case of the first generation
hardware? Just send press and release events directly from the ISR.

That timer looks like a software debounce to prevent unexpected and
meaningless interrupt/event caused by quick press/release.   

Right, but in case of the first generation hardware we schedule the
timer immediately (expire == 0) and do not check state of the hardware
in the timer handler, but rather simply emit down/up events, so we do
not really get any benefit from the timer (again, I am talking about
first generation hardware only).

Thanks.

-- 
Dmitry