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Subject: Re: [PATCH] platform/x86: intel-hid: Use hp-wireless for rfkill on HP
 platforms
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
In-Reply-To: <4d0714fe5e2548b6b638ea447ad19490@AUSX13MPC105.AMER.DELL.COM>
Date:   Thu, 11 Jun 2020 15:16:18 +0800
Cc:     Alex Hung <alex.hung@canonical.com>, dvhart@infradead.org,
        andy@infradead.org, platform-driver-x86@vger.kernel.org,
        linux-kernel@vger.kernel.org
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Message-Id: <82013BD4-B247-4E4E-94AB-1BEF8403E6E6@canonical.com>
References: <20200610153747.27040-1-kai.heng.feng@canonical.com>
 <4d0714fe5e2548b6b638ea447ad19490@AUSX13MPC105.AMER.DELL.COM>
To:     Mario Limonciello <mario.limonciello@dell.com>
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> On Jun 10, 2020, at 23:49, mario.limonciello@dell.com wrote:
> 
>> -----Original Message-----
>> From: platform-driver-x86-owner@vger.kernel.org <platform-driver-x86-
>> owner@vger.kernel.org> On Behalf Of Kai-Heng Feng
>> Sent: Wednesday, June 10, 2020 10:38 AM
>> To: alex.hung@canonical.com
>> Cc: Kai-Heng Feng; Darren Hart; Andy Shevchenko; open list:INTEL HID EVENT
>> DRIVER; open list
>> Subject: [PATCH] platform/x86: intel-hid: Use hp-wireless for rfkill on HP
>> platforms
>> 
>> 
>> [EXTERNAL EMAIL]
>> 
>> Wireless hotkey on HP platforms can trigger two events, if both
>> hp-wireless and intel-hid are supported. Two events at the same time
>> renders wireless hotkey useless.
>> 
>> HP confirmed that hp-wireless (HPQ6001) should always be the canonical
>> source of wireless hotkey event, so skip registering rfkill hotkey if
>> HPQ6001 is present.
>> 
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>> ---
>> drivers/platform/x86/intel-hid.c | 31 ++++++++++++++++++++++++++++++-
>> 1 file changed, 30 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/platform/x86/intel-hid.c b/drivers/platform/x86/intel-
>> hid.c
>> index 9ee79b74311c..31091c8faf70 100644
>> --- a/drivers/platform/x86/intel-hid.c
>> +++ b/drivers/platform/x86/intel-hid.c
>> @@ -25,6 +25,8 @@ static const struct acpi_device_id intel_hid_ids[] = {
>> };
>> MODULE_DEVICE_TABLE(acpi, intel_hid_ids);
>> 
>> +static bool hp_wireless_present;
>> +
>> /* In theory, these are HID usages. */
>> static const struct key_entry intel_hid_keymap[] = {
>> 	/* 1: LSuper (Page 0x07, usage 0xE3) -- unclear what to do */
>> @@ -49,6 +51,29 @@ static const struct key_entry intel_hid_keymap[] = {
>> 	{ KE_END },
>> };
>> 
>> +static const struct key_entry intel_hid_no_rfkill_keymap[] = {
>> +	/* 1: LSuper (Page 0x07, usage 0xE3) -- unclear what to do */
>> +	/* 2: Toggle SW_ROTATE_LOCK -- easy to implement if seen in wild */
>> +	{ KE_KEY, 3, { KEY_NUMLOCK } },
>> +	{ KE_KEY, 4, { KEY_HOME } },
>> +	{ KE_KEY, 5, { KEY_END } },
>> +	{ KE_KEY, 6, { KEY_PAGEUP } },
>> +	{ KE_KEY, 7, { KEY_PAGEDOWN } },
>> +	/* 8: rfkill -- use hp-wireless instead */
>> +	{ KE_KEY, 9, { KEY_POWER } },
>> +	{ KE_KEY, 11, { KEY_SLEEP } },
>> +	/* 13 has two different meanings in the spec -- ignore it. */
>> +	{ KE_KEY, 14, { KEY_STOPCD } },
>> +	{ KE_KEY, 15, { KEY_PLAYPAUSE } },
>> +	{ KE_KEY, 16, { KEY_MUTE } },
>> +	{ KE_KEY, 17, { KEY_VOLUMEUP } },
>> +	{ KE_KEY, 18, { KEY_VOLUMEDOWN } },
>> +	{ KE_KEY, 19, { KEY_BRIGHTNESSUP } },
>> +	{ KE_KEY, 20, { KEY_BRIGHTNESSDOWN } },
>> +	/* 27: wake -- needs special handling */
>> +	{ KE_END },
>> +};
>> +
>> /* 5 button array notification value. */
>> static const struct key_entry intel_array_keymap[] = {
>> 	{ KE_KEY,    0xC2, { KEY_LEFTMETA } },                /* Press */
>> @@ -317,7 +342,8 @@ static int intel_hid_input_setup(struct platform_device
>> *device)
>> 	if (!priv->input_dev)
>> 		return -ENOMEM;
>> 
>> -	ret = sparse_keymap_setup(priv->input_dev, intel_hid_keymap, NULL);
>> +	ret = sparse_keymap_setup(priv->input_dev, hp_wireless_present ?
>> +			intel_hid_no_rfkill_keymap : intel_hid_keymap, NULL);
>> 	if (ret)
>> 		return ret;
>> 
>> @@ -575,6 +601,9 @@ check_acpi_dev(acpi_handle handle, u32 lvl, void
>> *context, void **rv)
>> 			dev_info(&dev->dev,
>> 				 "intel-hid: created platform device\n");
>> 
>> +	if (!strcmp(acpi_device_hid(dev), "HPQ6001"))
>> +		hp_wireless_present = true;
> 
> Just having the ACPI device present doesn't actually mean that the user
> has a kernel compiled with hp-wireless or that it has finished initializing.

We can use IS_REACHEABLE() to see if it's compiled.

> 
> I would think this needs a better handshake in case hp-wireless was unloaded
> or not present so the event could still come through intel-hid in this
> circumstance.

However, it's hard to determine if the other driver has finished initialization or any form of cross module handshake.
Can you please point me to any good example if there's one?

> 
>> +
>> 	return AE_OK;
>> }
>> 
>> --
>> 2.17.1