> Hi Zhang,
>
> On Thu, Nov 19, 2020 at 03:01:19PM +0800, Zhang Qilong wrote:
> > In omap4_keypad_probe, the patch fix several bugs.
> >
> > 1) pm_runtime_get_sync will increment pm usage counter even it
> > failed. Forgetting to pm_runtime_put_noidle will result in
> > reference leak.
> >
> > 2) In err_unmap, forget to disable runtime of device,
> > pm_runtime_enable will increase power disable depth. Thus a
> > pairing decrement is needed on the error handling path to keep
> > it balanced.
> >
> > 3) In err_pm_disable, it will call pm_runtime_put_sync twice not
> > one time.
> >
> > And we add the pm_runtime_put_noidle when pm_runtime_get_sync failed
> > for 1). Move pm_runtime_disable to the err_unmap branch for 2). Move
> > the input_register_device ahead for 3).
> >
> > Fixes: f77621cc640a7 ("Input: omap-keypad - dynamically handle
> > register offsets")
> > Fixes: 5ad567ffbaf20 ("Input: Input: omap4-keypad - wire up runtime PM
> > handling")
> > Signed-off-by: Zhang Qilong <zhangqilong3@xxxxxxxxxx>
> > ---
> > drivers/input/keyboard/omap4-keypad.c | 13 +++++++------
> > 1 file changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/input/keyboard/omap4-keypad.c
> > b/drivers/input/keyboard/omap4-keypad.c
> > index d6c924032aaa..17abc8434af5 100644
> > --- a/drivers/input/keyboard/omap4-keypad.c
> > +++ b/drivers/input/keyboard/omap4-keypad.c
> > @@ -277,6 +277,7 @@ static int omap4_keypad_probe(struct
> platform_device *pdev)
> > pm_runtime_enable(&pdev->dev);
> > error = pm_runtime_get_sync(&pdev->dev);
> > if (error) {
> > + pm_runtime_put_noidle(&pdev->dev);
> > dev_err(&pdev->dev, "pm_runtime_get_sync() failed\n");
> > goto err_unmap;
> > }
> > @@ -349,20 +350,19 @@ static int omap4_keypad_probe(struct
> platform_device *pdev)
> > goto err_free_keymap;
> > }
> >
> > - device_init_wakeup(&pdev->dev, true);
> > - pm_runtime_put_sync(&pdev->dev);
> > -
> > error = input_register_device(keypad_data->input);
> > if (error < 0) {
> > dev_err(&pdev->dev, "failed to register input device\n");
> > - goto err_pm_disable;
> > + goto err_free_irq;
> > }
> >
> > + device_init_wakeup(&pdev->dev, true);
> > + pm_runtime_put_sync(&pdev->dev);
> > +
>
> I think your patch is technically correct, but I wonder if we should limit area of
> where we have device's clocks enabled to only where we need it. I.e.
> something like this:
>
> diff --git a/drivers/input/keyboard/omap4-keypad.c
> b/drivers/input/keyboard/omap4-keypad.c
> index d6c924032aaa..4ca754e95978 100644
> --- a/drivers/input/keyboard/omap4-keypad.c
> +++ b/drivers/input/keyboard/omap4-keypad.c
> @@ -186,12 +186,8 @@ static int omap4_keypad_open(struct input_dev
> *input)
> return 0;
> }
>
> -static void omap4_keypad_close(struct input_dev *input)
> +static void omap4_keypad_stop(struct omap4_keypad *keypad_data)
> {
> - struct omap4_keypad *keypad_data = input_get_drvdata(input);
> -
> - disable_irq(keypad_data->irq);
> -
> /* Disable interrupts and wake-up events */
> kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
> OMAP4_VAL_IRQDISABLE);
> @@ -200,7 +196,14 @@ static void omap4_keypad_close(struct input_dev
> *input)
> /* clear pending interrupts */
> kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
> kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
> +}
>
> +static void omap4_keypad_close(struct input_dev *input) {
> + struct omap4_keypad *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);
> @@ -223,13 +226,37 @@ static int omap4_keypad_parse_dt(struct device
> *dev,
> return 0;
> }
>
> +static int omap4_keypad_check_revision(struct device *dev,
> + struct omap4_keypad *keypad_data) {
> + unsigned int rev;
> +
> + rev = __raw_readl(keypad_data->base + OMAP4_KBD_REVISION);
> + rev &= 0x03 << 30;
> + rev >>= 30;
> + switch (rev) {
> + case KBD_REVISION_OMAP4:
> + keypad_data->reg_offset = 0x00;
> + keypad_data->irqreg_offset = 0x00;
> + break;
> + case KBD_REVISION_OMAP5:
> + keypad_data->reg_offset = 0x10;
> + keypad_data->irqreg_offset = 0x0c;
> + break;
> + default:
> + dev_err(dev, "Keypad reports unsupported revision %d", rev);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int omap4_keypad_probe(struct platform_device *pdev) {
> struct omap4_keypad *keypad_data;
> struct input_dev *input_dev;
> struct resource *res;
> unsigned int max_keys;
> - int rev;
> int irq;
> int error;
>
> @@ -269,41 +296,30 @@ static int omap4_keypad_probe(struct
> platform_device *pdev)
> goto err_release_mem;
> }
>
> + pm_runtime_enable(&pdev->dev);
>
> /*
> * Enable clocks for the keypad module so that we can read
> * revision register.
> */
> - pm_runtime_enable(&pdev->dev);
> error = pm_runtime_get_sync(&pdev->dev);
> if (error) {
> dev_err(&pdev->dev, "pm_runtime_get_sync() failed\n");
> - goto err_unmap;
> - }
> - rev = __raw_readl(keypad_data->base + OMAP4_KBD_REVISION);
> - rev &= 0x03 << 30;
> - rev >>= 30;
> - switch (rev) {
> - case KBD_REVISION_OMAP4:
> - keypad_data->reg_offset = 0x00;
> - keypad_data->irqreg_offset = 0x00;
> - break;
> - case KBD_REVISION_OMAP5:
> - keypad_data->reg_offset = 0x10;
> - keypad_data->irqreg_offset = 0x0c;
> - break;
> - default:
> - dev_err(&pdev->dev,
> - "Keypad reports unsupported revision %d", rev);
> - error = -EINVAL;
> - goto err_pm_put_sync;
> + pm_runtime_put_noidle(&pdev->dev);
I think it's OK, that is more clearly, here it should goto err_pm_disable ?
Thanks,
Zhang
> + } else {
> + error = omap4_keypad_check_revision(&pdev->dev, keypad_data);
> + if (!error) {
> + /* Ensure device does not raise interrupts */
> + omap4_keypad_stop(keypad_data);
> + }
> + pm_runtime_put_sync(&pdev->dev);
> }
>
> /* input device allocation */
> keypad_data->input = input_dev = input_allocate_device();
> if (!input_dev) {
> error = -ENOMEM;
> - goto err_pm_put_sync;
> + goto err_pm_disable;
> }
>
> input_dev->name = pdev->name;
> @@ -349,28 +365,25 @@ static int omap4_keypad_probe(struct
> platform_device *pdev)
> goto err_free_keymap;
> }
>
> - device_init_wakeup(&pdev->dev, true);
> - pm_runtime_put_sync(&pdev->dev);
> -
> error = input_register_device(keypad_data->input);
> if (error < 0) {
> dev_err(&pdev->dev, "failed to register input device\n");
> - goto err_pm_disable;
> + goto err_free_irq;
> }
>
> + device_init_wakeup(&pdev->dev, true);
> platform_set_drvdata(pdev, keypad_data);
> +
> return 0;
>
> -err_pm_disable:
> - pm_runtime_disable(&pdev->dev);
> +err_free_irq:
> free_irq(keypad_data->irq, keypad_data);
> err_free_keymap:
> kfree(keypad_data->keymap);
> err_free_input:
> input_free_device(input_dev);
> -err_pm_put_sync:
> - pm_runtime_put_sync(&pdev->dev);
> -err_unmap:
> +err_pm_disable:
> + pm_runtime_disable(&pdev->dev);
> iounmap(keypad_data->base);
> err_release_mem:
> release_mem_region(res->start, resource_size(res));
>
> > platform_set_drvdata(pdev, keypad_data);
> > return 0;
> >
> > -err_pm_disable:
> > - pm_runtime_disable(&pdev->dev);
> > +err_free_irq:
> > free_irq(keypad_data->irq, keypad_data);
> > err_free_keymap:
> > kfree(keypad_data->keymap);
> > @@ -371,6 +371,7 @@ static int omap4_keypad_probe(struct
> > platform_device *pdev)
> > err_pm_put_sync:
> > pm_runtime_put_sync(&pdev->dev);
> > err_unmap:
> > + pm_runtime_disable(&pdev->dev);
> > iounmap(keypad_data->base);
> > err_release_mem:
> > release_mem_region(res->start, resource_size(res));
> > --
> > 2.25.4
> >
>
> Thanks.
>
> --
> Dmitry
