diff mbox series

[3/4] Input: omap4-keypad - use PM runtime to check keys for errata

Message ID 20210106125822.31315-4-tony@atomide.com
State New
Headers show
Series None | expand

Commit Message

Tony Lindgren Jan. 6, 2021, 12:58 p.m. UTC
We are still missing handling for errata i689 related issues for the
case where we never see a key up interrupt for the last pressed key.

To fix the issue, we must scan the key state again after the keyboard
controller has idled to check if a key up event was missed. This is
described in the omap4 silicon errata documentation for Errata ID i689
"1.32 Keyboard Key Up Event Can Be Missed":

"When a key is released for a time shorter than the debounce time,
 in-between 2 key press (KP1 and KP2), the keyboard state machine will go
 to idle mode and will never detect the key release (after KP1, and also
 after KP2), and thus will never generate a new IRQ indicating the key
 release."

We can use PM runtime autosuspend features to check the keyboard state
again after it enters idle. We have the hardware support for clock
auto gating, and the keyboard is capable of generating wake-up events
in runtime suspended state.

Cc: Arthur Demchenkov <spinal.by@gmail.com>
Cc: Carl Philipp Klemm <philipp@uvos.xyz>
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: ruleh <ruleh@gmx.de>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/input/keyboard/omap4-keypad.c | 105 +++++++++++++++++++++++---
 1 file changed, 94 insertions(+), 11 deletions(-)

Comments

kernel test robot Jan. 6, 2021, 3:33 p.m. UTC | #1
Hi Tony,

I love your patch! Perhaps something to improve:

[auto build test WARNING on input/next]
[also build test WARNING on linus/master v5.11-rc2 next-20210104]
[cannot apply to hid/for-next linux/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Tony-Lindgren/Lost-key-up-interrupt-handling-for-omap4-keypad/20210106-210045
base:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git next
config: openrisc-randconfig-s031-20210106 (attached as .config)
compiler: or1k-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-208-g46a52ca4-dirty
        # https://github.com/0day-ci/linux/commit/69f44d8d3d1568dd3f330a46f6173a1bfc372ebd
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Tony-Lindgren/Lost-key-up-interrupt-handling-for-omap4-keypad/20210106-210045
        git checkout 69f44d8d3d1568dd3f330a46f6173a1bfc372ebd
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=openrisc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/input/keyboard/omap4-keypad.c: In function 'omap4_keypad_scan_keys':
   drivers/input/keyboard/omap4-keypad.c:162:6: warning: variable 'keys_up' set but not used [-Wunused-but-set-variable]
     162 |  int keys_up, keys_down;
         |      ^~~~~~~
   drivers/input/keyboard/omap4-keypad.c: In function 'omap4_keypad_irq_thread_fn':
>> drivers/input/keyboard/omap4-keypad.c:192:7: warning: variable 'down_events' set but not used [-Wunused-but-set-variable]
     192 |  bool down_events;
         |       ^~~~~~~~~~~
   At top level:
   drivers/input/keyboard/omap4-keypad.c:536:32: warning: 'omap4_keypad_pm_ops' defined but not used [-Wunused-const-variable=]
     536 | static const struct dev_pm_ops omap4_keypad_pm_ops = {
         |                                ^~~~~~~~~~~~~~~~~~~


vim +/down_events +192 drivers/input/keyboard/omap4-keypad.c

   158	
   159	static bool omap4_keypad_scan_keys(struct omap4_keypad *keypad_data, bool clear)
   160	{
   161		struct input_dev *input_dev = keypad_data->input;
 > 162		int keys_up, keys_down;
   163		u32 low, high;
   164		u64 keys = 0;
   165	
   166		mutex_lock(&keypad_data->lock);
   167		if (!clear) {
   168			low = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0);
   169			high = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32);
   170			keys = low | (u64)high << 32;
   171		}
   172	
   173		/* Scan for key up events for lost key-up interrupts */
   174		keys_up = omap4_keypad_scan_state(keypad_data, keys, false);
   175	
   176		/* Scan for key down events */
   177		keys_down = omap4_keypad_scan_state(keypad_data, keys, true);
   178	
   179		input_sync(input_dev);
   180	
   181		keypad_data->keys = keys;
   182	
   183		mutex_unlock(&keypad_data->lock);
   184	
   185		return keys_down;
   186	}
   187	
   188	static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id)
   189	{
   190		struct omap4_keypad *keypad_data = dev_id;
   191		struct device *dev = keypad_data->input->dev.parent;
 > 192		bool down_events;
   193		int error;
   194	
   195		error = pm_runtime_get_sync(dev);
   196		if (error < 0) {
   197			pm_runtime_put_noidle(dev);
   198	
   199			return IRQ_NONE;
   200		}
   201	
   202		down_events = omap4_keypad_scan_keys(keypad_data, false);
   203	
   204		/* clear pending interrupts */
   205		kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
   206				 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
   207	
   208		pm_runtime_mark_last_busy(dev);
   209		pm_runtime_put_autosuspend(dev);
   210	
   211		return IRQ_HANDLED;
   212	}
   213	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Dmitry Torokhov Jan. 10, 2021, 6:34 a.m. UTC | #2
Hi Tony,

On Wed, Jan 06, 2021 at 02:58:21PM +0200, Tony Lindgren wrote:
> @@ -301,6 +348,7 @@ static int omap4_keypad_probe(struct platform_device *pdev)

>  	}

>  

>  	keypad_data->irq = irq;

> +	mutex_init(&keypad_data->lock);

>  

>  	error = omap4_keypad_parse_dt(&pdev->dev, keypad_data);

>  	if (error)

> @@ -320,6 +368,8 @@ static int omap4_keypad_probe(struct platform_device *pdev)

>  		goto err_release_mem;

>  	}

>  

> +	pm_runtime_use_autosuspend(&pdev->dev);

> +	pm_runtime_set_autosuspend_delay(&pdev->dev, OMAP4_KEYPAD_AUTOIDLE_MS);


This, and corresponding changes in open() and close() seem like a
separate improvement. Do you mind splitting them into a separate patch,
and have the missing key release fix go on top of it?

Thanks.

-- 
Dmitry
Tony Lindgren Jan. 10, 2021, 4:49 p.m. UTC | #3
* Dmitry Torokhov <dmitry.torokhov@gmail.com> [210110 06:34]:
> Hi Tony,
> 
> On Wed, Jan 06, 2021 at 02:58:21PM +0200, Tony Lindgren wrote:
> > @@ -301,6 +348,7 @@ static int omap4_keypad_probe(struct platform_device *pdev)
> >  	}
> >  
> >  	keypad_data->irq = irq;
> > +	mutex_init(&keypad_data->lock);
> >  
> >  	error = omap4_keypad_parse_dt(&pdev->dev, keypad_data);
> >  	if (error)
> > @@ -320,6 +368,8 @@ static int omap4_keypad_probe(struct platform_device *pdev)
> >  		goto err_release_mem;
> >  	}
> >  
> > +	pm_runtime_use_autosuspend(&pdev->dev);
> > +	pm_runtime_set_autosuspend_delay(&pdev->dev, OMAP4_KEYPAD_AUTOIDLE_MS);
> 
> This, and corresponding changes in open() and close() seem like a
> separate improvement. Do you mind splitting them into a separate patch,
> and have the missing key release fix go on top of it?

Sure will do.

Thanks,

Tony
diff mbox series

Patch

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
@@ -60,6 +60,7 @@ 
 	((((dbms) * 1000) / ((1 << ((ptv) + 1)) * (1000000 / 32768))) - 1)
 #define OMAP4_VAL_DEBOUNCINGTIME_16MS					\
 	OMAP4_KEYPAD_DEBOUNCINGTIME_MS(16, OMAP4_KEYPAD_PTV_DIV_128)
+#define OMAP4_KEYPAD_AUTOIDLE_MS	50	/* Approximate measured time */
 
 enum {
 	KBD_REVISION_OMAP4 = 0,
@@ -71,6 +72,7 @@  struct omap4_keypad {
 
 	void __iomem *base;
 	unsigned int irq;
+	struct mutex lock;		/* for key scan */
 
 	unsigned int rows;
 	unsigned int cols;
@@ -154,17 +156,19 @@  static irqreturn_t omap4_keypad_irq_handler(int irq, void *dev_id)
 	return IRQ_NONE;
 }
 
-static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id)
+static bool omap4_keypad_scan_keys(struct omap4_keypad *keypad_data, bool clear)
 {
-	struct omap4_keypad *keypad_data = dev_id;
 	struct input_dev *input_dev = keypad_data->input;
 	int keys_up, keys_down;
 	u32 low, high;
-	u64 keys;
+	u64 keys = 0;
 
-	low = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0);
-	high = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32);
-	keys = low | (u64)high << 32;
+	mutex_lock(&keypad_data->lock);
+	if (!clear) {
+		low = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0);
+		high = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32);
+		keys = low | (u64)high << 32;
+	}
 
 	/* Scan for key up events for lost key-up interrupts */
 	keys_up = omap4_keypad_scan_state(keypad_data, keys, false);
@@ -176,18 +180,49 @@  static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id)
 
 	keypad_data->keys = keys;
 
+	mutex_unlock(&keypad_data->lock);
+
+	return keys_down;
+}
+
+static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id)
+{
+	struct omap4_keypad *keypad_data = dev_id;
+	struct device *dev = keypad_data->input->dev.parent;
+	bool down_events;
+	int error;
+
+	error = pm_runtime_get_sync(dev);
+	if (error < 0) {
+		pm_runtime_put_noidle(dev);
+
+		return IRQ_NONE;
+	}
+
+	down_events = omap4_keypad_scan_keys(keypad_data, false);
+
 	/* clear pending interrupts */
 	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
 			 kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
 
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
 	return IRQ_HANDLED;
 }
 
 static int omap4_keypad_open(struct input_dev *input)
 {
 	struct omap4_keypad *keypad_data = input_get_drvdata(input);
+	struct device *dev = input->dev.parent;
+	int error;
 
-	pm_runtime_get_sync(input->dev.parent);
+	error = pm_runtime_get_sync(dev);
+	if (error < 0) {
+		pm_runtime_put_noidle(dev);
+
+		return error;
+	}
 
 	disable_irq(keypad_data->irq);
 
@@ -206,6 +241,9 @@  static int omap4_keypad_open(struct input_dev *input)
 
 	enable_irq(keypad_data->irq);
 
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
 	return 0;
 }
 
@@ -223,14 +261,23 @@  static void omap4_keypad_stop(struct omap4_keypad *keypad_data)
 
 static void omap4_keypad_close(struct input_dev *input)
 {
-	struct omap4_keypad *keypad_data;
+	struct omap4_keypad *keypad_data = input_get_drvdata(input);
+	struct device *dev = input->dev.parent;
+	int error;
+
+	error = pm_runtime_get_sync(dev);
+	if (error < 0) {
+		pm_runtime_put_noidle(dev);
+
+		return;
+	}
 
-	keypad_data = input_get_drvdata(input);
 	disable_irq(keypad_data->irq);
 	omap4_keypad_stop(keypad_data);
 	enable_irq(keypad_data->irq);
 
-	pm_runtime_put_sync(input->dev.parent);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
 }
 
 static int omap4_keypad_parse_dt(struct device *dev,
@@ -301,6 +348,7 @@  static int omap4_keypad_probe(struct platform_device *pdev)
 	}
 
 	keypad_data->irq = irq;
+	mutex_init(&keypad_data->lock);
 
 	error = omap4_keypad_parse_dt(&pdev->dev, keypad_data);
 	if (error)
@@ -320,6 +368,8 @@  static int omap4_keypad_probe(struct platform_device *pdev)
 		goto err_release_mem;
 	}
 
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, OMAP4_KEYPAD_AUTOIDLE_MS);
 	pm_runtime_enable(&pdev->dev);
 
 	/*
@@ -337,7 +387,6 @@  static int omap4_keypad_probe(struct platform_device *pdev)
 			/* Ensure device does not raise interrupts */
 			omap4_keypad_stop(keypad_data);
 		}
-		pm_runtime_put_sync(&pdev->dev);
 	}
 	if (error)
 		goto err_pm_disable;
@@ -406,6 +455,9 @@  static int omap4_keypad_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, keypad_data);
 
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
 	return 0;
 
 err_free_irq:
@@ -415,6 +467,8 @@  static int omap4_keypad_probe(struct platform_device *pdev)
 err_free_input:
 	input_free_device(input_dev);
 err_pm_disable:
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	iounmap(keypad_data->base);
 err_release_mem:
@@ -433,6 +487,7 @@  static int omap4_keypad_remove(struct platform_device *pdev)
 
 	free_irq(keypad_data->irq, keypad_data);
 
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
 	input_unregister_device(keypad_data->input);
@@ -454,6 +509,34 @@  static const struct of_device_id omap_keypad_dt_match[] = {
 };
 MODULE_DEVICE_TABLE(of, omap_keypad_dt_match);
 
+/*
+ * Errata ID i689 "1.32 Keyboard Key Up Event Can Be Missed".
+ * Interrupt may not happen for key-up events.
+ */
+static int __maybe_unused omap4_keypad_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct omap4_keypad *keypad_data = platform_get_drvdata(pdev);
+	bool events;
+	u32 active;
+
+	active = kbd_readl(keypad_data, OMAP4_KBD_STATEMACHINE);
+	if (active) {
+		pm_runtime_mark_last_busy(dev);
+		return -EBUSY;
+	}
+
+	events = omap4_keypad_scan_keys(keypad_data, true);
+	if (events)
+		dev_info(dev, "cleared stuck events on idle\n");
+
+	return 0;
+}
+
+static const struct dev_pm_ops omap4_keypad_pm_ops = {
+	SET_RUNTIME_PM_OPS(omap4_keypad_runtime_suspend, NULL, NULL)
+};
+
 static struct platform_driver omap4_keypad_driver = {
 	.probe		= omap4_keypad_probe,
 	.remove		= omap4_keypad_remove,