| Message ID | 20160419165325.GA2881@dtor-ws (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Dmitry, > Am 19.04.2016 um 18:53 schrieb Dmitry Torokhov <dmitry.torokhov@gmail.com>: > > On Tue, Apr 19, 2016 at 10:05:08AM +0200, H. Nikolaus Schaller wrote: >> >>> Am 19.04.2016 um 09:57 schrieb Dmitry Torokhov <dmitry.torokhov@gmail.com>: >>> >>> On Tue, Apr 19, 2016 at 09:33:10AM +0200, H. Nikolaus Schaller wrote: >>>> >>>>> Am 18.04.2016 um 23:12 schrieb Dmitry Torokhov <dmitry.torokhov@gmail.com>: >>>>> >>>>> On Mon, Apr 18, 2016 at 09:55:38PM +0200, H. Nikolaus Schaller wrote: >>>>>> commit 1f9e1470ab34 ("Input: twl6040-vibra - use devm functions") >>>>>> >>>>>> converted everything to devm but we still need to call >>>>>> input_unregister_device(info->input_dev) >>>>> >>>>> No, this is not needed, because devm-managed input devices will be >>>>> unregistered automatically. >>>> >>>> Well, it would, if the current driver would use devm for registration. But it appears not to do it that way (line 375): >>>> >>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/input/misc/twl6040-vibra.c?id=refs/tags/v4.6-rc4#n375 >>>> >>>> So we either have to fix line 375 or add the proposed explicit unregister call. >>>> >>>> Research shows me that you did propose devm_input_register_device() some years ago but this API was never included: >>>> >>>> https://lkml.org/lkml/2012/10/29/855 >>> >>> That's because we have what I mentioned in _OR_ portion of that email: >>> >>> /** >>> * devm_input_allocate_device - allocate managed input device >>> * @dev: device owning the input device being created >>> * >>> * Returns prepared struct input_dev or %NULL. >>> * >>> * Managed input devices do not need to be explicitly unregistered or >>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>> * freed as it will be done automatically when owner device unbinds from >>> * its driver (or binding fails). Once managed input device is allocated, >>> * it is ready to be set up and registered in the same fashion as regular >>> * input device. There are no special devm_input_device_[un]register() >>> * variants, regular ones work with both managed and unmanaged devices, >>> * should you need them. In most cases however, managed input device need >>> * not be explicitly unregistered or freed. >>> * >>> * NOTE: the owner device is set up as parent of input device and users >>> * should not override it. >>> */ >>> >> >> Hm. If I remember correctly (it is a while ago) we had to add this explicit >> unregister mechanism because we got ugly kernel panics otherwise. Indicating >> that the input device was still registered and *not* unregistered automatically. > > Ah, it is probably because we are messing up with input device's parent. > Can you please try the patch below? > Appears to have no new side-effects and the original problem does not appear again. BR and thanks, Nikolaus -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/input/misc/twl6040-vibra.c b/drivers/input/misc/twl6040-vibra.c index 0c853c2..53e33fa 100644 --- a/drivers/input/misc/twl6040-vibra.c +++ b/drivers/input/misc/twl6040-vibra.c @@ -357,7 +357,6 @@ static int twl6040_vibra_probe(struct platform_device *pdev) info->input_dev->name = "twl6040:vibrator"; info->input_dev->id.version = 1; - info->input_dev->dev.parent = pdev->dev.parent; info->input_dev->close = twl6040_vibra_close; __set_bit(FF_RUMBLE, info->input_dev->ffbit);