Commit aacb455d authored by Hans de Goede's avatar Hans de Goede
Browse files

platform/x86: panasonic-laptop: filter out duplicate volume up/down/mute keypresses 



On some Panasonic models the volume up/down/mute keypresses get
reported both through the Panasonic ACPI HKEY interface as well as
through the atkbd device.

Filter out the atkbd scan-codes for these to avoid reporting presses
twice.

Note normally we would leave the filtering of these to userspace by mapping
the scan-codes to KEY_UNKNOWN through /lib/udev/hwdb.d/60-keyboard.hwdb.
However in this case that would cause regressions since we were filtering
the Panasonic ACPI HKEY events before, so filter these in the kernel.

Fixes: ed83c917 ("platform/x86: panasonic-laptop: Resolve hotkey double trigger bug")
Reported-and-tested-by: default avatarStefan Seyfried <seife+kernel@b1-systems.com>
Reported-and-tested-by: default avatarKenneth Chan <kenneth.t.chan@gmail.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220624112340.10130-7-hdegoede@redhat.com
parent 1f2c9de8

drivers/platform/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -946,6 +946,7 @@ config PANASONIC_LAPTOP 
	depends on INPUT && ACPI

	depends on BACKLIGHT_CLASS_DEVICE

	depends on ACPI_VIDEO=n || ACPI_VIDEO

	depends on SERIO_I8042 || SERIO_I8042 = n

	select INPUT_SPARSEKMAP

	help

	  This driver adds support for access to backlight control and hotkeys

drivers/platform/x86/panasonic-laptop.c

+41 −0
Original line number Diff line number Diff line
@@ -122,6 +122,7 @@ 
#include <linux/acpi.h>

#include <linux/backlight.h>

#include <linux/ctype.h>

#include <linux/i8042.h>

#include <linux/init.h>

#include <linux/input.h>

#include <linux/input/sparse-keymap.h>
@@ -129,6 +130,7 @@ 
#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/seq_file.h>

#include <linux/serio.h>

#include <linux/slab.h>

#include <linux/types.h>

#include <linux/uaccess.h>
@@ -241,6 +243,42 @@ struct pcc_acpi { 
	struct platform_device	*platform;

};



/*

 * On some Panasonic models the volume up / down / mute keys send duplicate

 * keypress events over the PS/2 kbd interface, filter these out.

 */

static bool panasonic_i8042_filter(unsigned char data, unsigned char str,

				   struct serio *port)

{

	static bool extended;



	if (str & I8042_STR_AUXDATA)

		return false;



	if (data == 0xe0) {

		extended = true;

		return true;

	} else if (extended) {

		extended = false;



		switch (data & 0x7f) {

		case 0x20: /* e0 20 / e0 a0, Volume Mute press / release */

		case 0x2e: /* e0 2e / e0 ae, Volume Down press / release */

		case 0x30: /* e0 30 / e0 b0, Volume Up press / release */

			return true;

		default:

			/*

			 * Report the previously filtered e0 before continuing

			 * with the next non-filtered byte.

			 */

			serio_interrupt(port, 0xe0, 0);

			return false;

		}

	}



	return false;

}



/* method access functions */

static int acpi_pcc_write_sset(struct pcc_acpi *pcc, int func, int val)

{
@@ -1006,6 +1044,7 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device) 
		pcc->platform = NULL;

	}



	i8042_install_filter(panasonic_i8042_filter);

	return 0;



out_platform:
@@ -1029,6 +1068,8 @@ static int acpi_pcc_hotkey_remove(struct acpi_device *device) 
	if (!device || !pcc)

		return -EINVAL;



	i8042_remove_filter(panasonic_i8042_filter);



	if (pcc->platform) {

		device_remove_file(&pcc->platform->dev, &dev_attr_cdpower);

		platform_device_unregister(pcc->platform);