[RFC/RFT] HID: primax: Fix wireless keyboards descriptor

[RFC/RFT] HID: primax: Fix wireless keyboards descriptor

[Nicolas Saenz Julienne]

A whole set of Primax manufactured wireless keyboards won't work out of
the box as they provide wrong HID descriptors. In this case the offense
being defining the "Usage Maximum/Minimum" local items before the "Usage
Page". This will make the parser use the previous "Usage Page" on those
local items, generating a wrong HID report. This is not a parser error
as the spec clearly states that "Usage Page" applies to any item that
follows it (see 6.2.2.7).

In other words, we get this:

15 00          Logical Minimum (0),
26 ff 00       Logical Maximum (255),
19 00          Usage Minimum (00h),
2a ff 00       Usage Maximum (FFh),
05 07          Usage Page (Keyboard),          ; Keyboard/keypad (07h)
75 08          Report Size (8),
95 06          Report Count (6),
81 00          Input,

Yet they meant this:

15 00          Logical Minimum (0),
26 ff 00       Logical Maximum (255),
05 07          Usage Page (Keyboard),          ; Keyboard/keypad (07h)
19 00          Usage Minimum (00h),
2a ff 00       Usage Maximum (FFh),
75 08          Report Size (8),
95 06          Report Count (6),
81 00          Input,

This patch fixes the issue by overwriting the offending report with a
correct one.

This was made thanks to the user's answers provided here, also full HID
descriptors are available there:
https://unix.stackexchange.com/questions/377830/linux-hid-driver-for-primax-wireless-keyboards/

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---

NOTE: This is an RFC as I'm unable to test my fix. Apart from the
  devices mentioned in the patch there is a whole list of them, yet I
  didn't include them as I was unable to access their HID descriptors.

 drivers/hid/hid-ids.h    |  3 +++
 drivers/hid/hid-primax.c | 30 +++++++++++++++++++++++++++++-
 drivers/hid/hid-quirks.c |  3 +++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 24f846d67478..b39f9f36d41f 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -714,6 +714,7 @@
 #define USB_DEVICE_ID_LENOVO_TPPRODOCK	0x6067
 #define USB_DEVICE_ID_LENOVO_X1_COVER	0x6085
 #define USB_DEVICE_ID_LENOVO_X1_TAB	0x60a3
+#define USB_DEVICE_ID_LENOVO_WIRELESS_PROFESSIONAL	0x609b
 
 #define USB_VENDOR_ID_LG		0x1fd2
 #define USB_DEVICE_ID_LG_MULTITOUCH	0x0064
@@ -1225,6 +1226,8 @@
 #define USB_DEVICE_ID_PRIMAX_REZEL	0x4e72
 #define USB_DEVICE_ID_PRIMAX_PIXART_MOUSE_4D0F	0x4d0f
 #define USB_DEVICE_ID_PRIMAX_PIXART_MOUSE_4E22	0x4e22
+#define USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E63	0x4e63
+#define USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E80	0x4e80
 
 
 #define USB_VENDOR_ID_RISO_KAGAKU	0x1294	/* Riso Kagaku Corp. */
diff --git a/drivers/hid/hid-primax.c b/drivers/hid/hid-primax.c
index 3a1c3c4c50dc..033f6660e8b6 100644
--- a/drivers/hid/hid-primax.c
+++ b/drivers/hid/hid-primax.c
@@ -2,9 +2,11 @@
  * HID driver for primax and similar keyboards with in-band modifiers
  *
  * Copyright 2011 Google Inc. All Rights Reserved
+ * Copyright 2019 Nicolas Saenz Julienne
  *
- * Author:
+ * Authors:
  *	Terry Lambert <tlambert@google.com>
+ *	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
@@ -27,6 +29,9 @@ static int px_raw_event(struct hid_device *hid, struct hid_report *report,
 {
 	int idx = size;
 
+	if (hid->product != USB_DEVICE_ID_PRIMAX_KEYBOARD)
+		return 0;
+
 	switch (report->id) {
 	case 0:		/* keyboard input */
 		/*
@@ -64,8 +69,29 @@ static int px_raw_event(struct hid_device *hid, struct hid_report *report,
 	return 0;
 }
 
+/*
+ * Some Primax manufactured keyboards set "Usage Minimum/Maximum" values before
+ * setting the "Usage Page". This is not supported as per spec 6.2.2.7.
+ */
+static __u8 *px_fixup(struct hid_device *hid, __u8 *rdesc, unsigned int *rsize)
+{
+	__u8 wrong_report[] = { 0x19, 0x00, 0x2a, 0xff, 0x05, 0x07 };
+	__u8 fixed_report[] = { 0x05, 0x07, 0x19, 0x00, 0x2a, 0xff };
+
+	if (*rsize > 57 &&
+	    !memcmp(&rdesc[51], wrong_report, ARRAY_SIZE(wrong_report))) {
+		hid_info(hid, "fixing up Primax report descriptor\n");
+		memcpy(&rdesc[51], fixed_report, ARRAY_SIZE(fixed_report));
+	}
+
+	return rdesc;
+}
+
 static const struct hid_device_id px_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E63) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E80) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_WIRELESS_PROFESSIONAL) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, px_devices);
@@ -74,8 +100,10 @@ static struct hid_driver px_driver = {
 	.name = "primax",
 	.id_table = px_devices,
 	.raw_event = px_raw_event,
+	.report_fixup = px_fixup,
 };
 module_hid_driver(px_driver);
 
 MODULE_AUTHOR("Terry Lambert <tlambert@google.com>");
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de");
 MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index 94088c0ed68a..9fd256fea231 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -563,6 +563,9 @@ static const struct hid_device_id hid_have_special_driver[] = {
 #endif
 #if IS_ENABLED(CONFIG_HID_PRIMAX)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E63) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E80) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_WIRELESS_PROFESSIONAL) },
 #endif
 #if IS_ENABLED(CONFIG_HID_PRODIKEYS)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS, USB_DEVICE_ID_PRODIKEYS_PCMIDI) },
-- 
2.20.1

RE: [RFC/RFT] HID: primax: Fix wireless keyboards descriptor

[Junge, Terry]

This could also be a parser error. In the HID specification section 6.2.2.8 it states that the last declared Usage Page is applied to Usages when the Main item is encountered.

"If the bSize field = 1 or 2 then the Usage is interpreted as an unsigned value
that selects a Usage ID on the currently defined Usage Page. When the parser
encounters a main item it concatenates the last declared Usage Page with a
Usage to form a complete usage value. Extended usages can be used to
override the currently defined Usage Page for individual usages."

-----Original Message-----
From: linux-input-owner@vger.kernel.org <linux-input-owner@vger.kernel.org> On Behalf Of Nicolas Saenz Julienne
Sent: Thursday, February 28, 2019 5:56 AM
To: Jiri Kosina <jikos@kernel.org>; Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: oneukum@suse.de; Nicolas Saenz Julienne <nsaenzjulienne@suse.de>; linux-input@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: [RFC/RFT] HID: primax: Fix wireless keyboards descriptor

A whole set of Primax manufactured wireless keyboards won't work out of the box as they provide wrong HID descriptors. In this case the offense being defining the "Usage Maximum/Minimum" local items before the "Usage Page". This will make the parser use the previous "Usage Page" on those local items, generating a wrong HID report. This is not a parser error as the spec clearly states that "Usage Page" applies to any item that follows it (see 6.2.2.7).

In other words, we get this:

15 00          Logical Minimum (0),
26 ff 00       Logical Maximum (255),
19 00          Usage Minimum (00h),
2a ff 00       Usage Maximum (FFh),
05 07          Usage Page (Keyboard),          ; Keyboard/keypad (07h)
75 08          Report Size (8),
95 06          Report Count (6),
81 00          Input,

Yet they meant this:

15 00          Logical Minimum (0),
26 ff 00       Logical Maximum (255),
05 07          Usage Page (Keyboard),          ; Keyboard/keypad (07h)
19 00          Usage Minimum (00h),
2a ff 00       Usage Maximum (FFh),
75 08          Report Size (8),
95 06          Report Count (6),
81 00          Input,

This patch fixes the issue by overwriting the offending report with a correct one.

This was made thanks to the user's answers provided here, also full HID descriptors are available there:
https://unix.stackexchange.com/questions/377830/linux-hid-driver-for-primax-wireless-keyboards/

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---

NOTE: This is an RFC as I'm unable to test my fix. Apart from the
  devices mentioned in the patch there is a whole list of them, yet I
  didn't include them as I was unable to access their HID descriptors.

 drivers/hid/hid-ids.h    |  3 +++
 drivers/hid/hid-primax.c | 30 +++++++++++++++++++++++++++++-  drivers/hid/hid-quirks.c |  3 +++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h index 24f846d67478..b39f9f36d41f 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -714,6 +714,7 @@
 #define USB_DEVICE_ID_LENOVO_TPPRODOCK	0x6067
 #define USB_DEVICE_ID_LENOVO_X1_COVER	0x6085
 #define USB_DEVICE_ID_LENOVO_X1_TAB	0x60a3
+#define USB_DEVICE_ID_LENOVO_WIRELESS_PROFESSIONAL	0x609b
 
 #define USB_VENDOR_ID_LG		0x1fd2
 #define USB_DEVICE_ID_LG_MULTITOUCH	0x0064
@@ -1225,6 +1226,8 @@
 #define USB_DEVICE_ID_PRIMAX_REZEL	0x4e72
 #define USB_DEVICE_ID_PRIMAX_PIXART_MOUSE_4D0F	0x4d0f
 #define USB_DEVICE_ID_PRIMAX_PIXART_MOUSE_4E22	0x4e22
+#define USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E63	0x4e63
+#define USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E80	0x4e80
 
 
 #define USB_VENDOR_ID_RISO_KAGAKU	0x1294	/* Riso Kagaku Corp. */
diff --git a/drivers/hid/hid-primax.c b/drivers/hid/hid-primax.c index 3a1c3c4c50dc..033f6660e8b6 100644
--- a/drivers/hid/hid-primax.c
+++ b/drivers/hid/hid-primax.c
@@ -2,9 +2,11 @@
  * HID driver for primax and similar keyboards with in-band modifiers
  *
  * Copyright 2011 Google Inc. All Rights Reserved
+ * Copyright 2019 Nicolas Saenz Julienne
  *
- * Author:
+ * Authors:
  *	Terry Lambert <tlambert@google.com>
+ *	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and @@ -27,6 +29,9 @@ static int px_raw_event(struct hid_device *hid, struct hid_report *report,  {
 	int idx = size;
 
+	if (hid->product != USB_DEVICE_ID_PRIMAX_KEYBOARD)
+		return 0;
+
 	switch (report->id) {
 	case 0:		/* keyboard input */
 		/*
@@ -64,8 +69,29 @@ static int px_raw_event(struct hid_device *hid, struct hid_report *report,
 	return 0;
 }
 
+/*
+ * Some Primax manufactured keyboards set "Usage Minimum/Maximum" 
+values before
+ * setting the "Usage Page". This is not supported as per spec 6.2.2.7.
+ */
+static __u8 *px_fixup(struct hid_device *hid, __u8 *rdesc, unsigned int 
+*rsize) {
+	__u8 wrong_report[] = { 0x19, 0x00, 0x2a, 0xff, 0x05, 0x07 };
+	__u8 fixed_report[] = { 0x05, 0x07, 0x19, 0x00, 0x2a, 0xff };
+
+	if (*rsize > 57 &&
+	    !memcmp(&rdesc[51], wrong_report, ARRAY_SIZE(wrong_report))) {
+		hid_info(hid, "fixing up Primax report descriptor\n");
+		memcpy(&rdesc[51], fixed_report, ARRAY_SIZE(fixed_report));
+	}
+
+	return rdesc;
+}
+
 static const struct hid_device_id px_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E63) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E80) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, 
+USB_DEVICE_ID_LENOVO_WIRELESS_PROFESSIONAL) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, px_devices);
@@ -74,8 +100,10 @@ static struct hid_driver px_driver = {
 	.name = "primax",
 	.id_table = px_devices,
 	.raw_event = px_raw_event,
+	.report_fixup = px_fixup,
 };
 module_hid_driver(px_driver);
 
 MODULE_AUTHOR("Terry Lambert <tlambert@google.com>");
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de");
 MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c index 94088c0ed68a..9fd256fea231 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -563,6 +563,9 @@ static const struct hid_device_id hid_have_special_driver[] = {  #endif  #if IS_ENABLED(CONFIG_HID_PRIMAX)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E63) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_WIRELESS_KEYBOARD_4E80) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, 
+USB_DEVICE_ID_LENOVO_WIRELESS_PROFESSIONAL) },
 #endif
 #if IS_ENABLED(CONFIG_HID_PRODIKEYS)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS, USB_DEVICE_ID_PRODIKEYS_PCMIDI) },
--
2.20.1

Re: [RFC/RFT] HID: primax: Fix wireless keyboards descriptor

[Nicolas Saenz Julienne]

[-- Attachment #1: Type: text/plain, Size: 1633 bytes --]

On Thu, 2019-02-28 at 17:02 +0000, Junge, Terry wrote:
> This could also be a parser error. In the HID specification section 6.2.2.8 it
> states that the last declared Usage Page is applied to Usages when the Main
> item is encountered.
> 
> "If the bSize field = 1 or 2 then the Usage is interpreted as an unsigned
> value
> that selects a Usage ID on the currently defined Usage Page. When the parser
> encounters a main item it concatenates the last declared Usage Page with a
> Usage to form a complete usage value. Extended usages can be used to
> override the currently defined Usage Page for individual usages."
> 

Hi Terry, thanks for the comment.
Just for the record the paragraph I cited on my patch is the following:

	6.2.2.7 Global Items

	[...]

	Usage Page: Unsigned integer specifying the current Usage Page. Since a
	usage are 32 bit values, Usage Page items can be used to conserve space
	in a report descriptor by setting the high order 16 bits of a
	subsequent usages. Any usage that follows which is defines* 16 bits or
	less is interpreted as a Usage ID and concatenated with the Usage Page
	to form a 32 bit Usage.

	* This is a spec errata, I belive it should say "defined"

As you can see they use the word "follows" which in my opinion contradicts the
paragraph you pointed out. That said I may be wrong, I'm not too good at
reading specs :).

I checked the HID parser and it's indeed written assuming local items are
preceded by a Usage Page. I'd be glad to fix it there, but it would be nice to
have the mantainer's opinion on the matter first.

Regards,
Nicolas


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [RFC/RFT] HID: primax: Fix wireless keyboards descriptor

[Benjamin Tissoires]

On Thu, Feb 28, 2019 at 7:01 PM Nicolas Saenz Julienne
<nsaenzjulienne@suse.de> wrote:
>
> On Thu, 2019-02-28 at 17:02 +0000, Junge, Terry wrote:
> > This could also be a parser error. In the HID specification section 6.2.2.8 it
> > states that the last declared Usage Page is applied to Usages when the Main
> > item is encountered.
> >
> > "If the bSize field = 1 or 2 then the Usage is interpreted as an unsigned
> > value
> > that selects a Usage ID on the currently defined Usage Page. When the parser
> > encounters a main item it concatenates the last declared Usage Page with a
> > Usage to form a complete usage value. Extended usages can be used to
> > override the currently defined Usage Page for individual usages."
> >
>
> Hi Terry, thanks for the comment.
> Just for the record the paragraph I cited on my patch is the following:
>
>         6.2.2.7 Global Items
>
>         [...]
>
>         Usage Page: Unsigned integer specifying the current Usage Page. Since a
>         usage are 32 bit values, Usage Page items can be used to conserve space
>         in a report descriptor by setting the high order 16 bits of a
>         subsequent usages. Any usage that follows which is defines* 16 bits or
>         less is interpreted as a Usage ID and concatenated with the Usage Page
>         to form a 32 bit Usage.
>
>         * This is a spec errata, I belive it should say "defined"
>
> As you can see they use the word "follows" which in my opinion contradicts the
> paragraph you pointed out. That said I may be wrong, I'm not too good at
> reading specs :).

I think you are both right (that is some decision making skills :-P).

I never saw a case where the Usage Page was after the Usage. And I
would lean towards Nicolas interpretation.
However, Terry's point is valid too, and by re-reading the two
paragraphs, one could argue that the "follows" of 6.2.2.7 could be
applied when the Main item is processed as in 6.2.2.8.

So I am going to base my decision on the "reference" driver. How well
behaves Windows with this particular keyboard?

If it behaves properly, then we better use the 6.2.2.8 version where
the Usage Page is only appended when there is a Main item. This means
we need to remember what size was the last Usage (and Min/Max), to
know if we should concatenate the 2.

Note that for every change that involves the generic parser, I'd like
a few tests added to `tests/test_keyboard.py in
https://gitlab.freedesktop.org/libevdev/hid-tools
Also note that the HID parser implementation in hid-tools follows the
kernel, so we might need to adjust it there too if we want to add high
level events. If you directly call `.call_input_event()` with raw
events, it should be fine.

>
> I checked the HID parser and it's indeed written assuming local items are
> preceded by a Usage Page. I'd be glad to fix it there, but it would be nice to
> have the mantainer's opinion on the matter first.
>

You've now got the opinion of one of the 2 maintainers, hope this helps :)

Cheers,
Benjamin

Re: [RFC/RFT] HID: primax: Fix wireless keyboards descriptor

[Nicolas Saenz Julienne]

[-- Attachment #1: Type: text/plain, Size: 3170 bytes --]

On Fri, 2019-03-01 at 10:48 +0100, Benjamin Tissoires wrote:
> On Thu, Feb 28, 2019 at 7:01 PM Nicolas Saenz Julienne
> <nsaenzjulienne@suse.de> wrote:
> > On Thu, 2019-02-28 at 17:02 +0000, Junge, Terry wrote:
> > > This could also be a parser error. In the HID specification section
> > > 6.2.2.8 it
> > > states that the last declared Usage Page is applied to Usages when the
> > > Main
> > > item is encountered.
> > > 
> > > "If the bSize field = 1 or 2 then the Usage is interpreted as an unsigned
> > > value
> > > that selects a Usage ID on the currently defined Usage Page. When the
> > > parser
> > > encounters a main item it concatenates the last declared Usage Page with a
> > > Usage to form a complete usage value. Extended usages can be used to
> > > override the currently defined Usage Page for individual usages."
> > > 
> > 
> > Hi Terry, thanks for the comment.
> > Just for the record the paragraph I cited on my patch is the following:
> > 
> >         6.2.2.7 Global Items
> > 
> >         [...]
> > 
> >         Usage Page: Unsigned integer specifying the current Usage Page.
> > Since a
> >         usage are 32 bit values, Usage Page items can be used to conserve
> > space
> >         in a report descriptor by setting the high order 16 bits of a
> >         subsequent usages. Any usage that follows which is defines* 16 bits
> > or
> >         less is interpreted as a Usage ID and concatenated with the Usage
> > Page
> >         to form a 32 bit Usage.
> > 
> >         * This is a spec errata, I belive it should say "defined"
> > 
> > As you can see they use the word "follows" which in my opinion contradicts
> > the
> > paragraph you pointed out. That said I may be wrong, I'm not too good at
> > reading specs :).
> 
> I think you are both right (that is some decision making skills :-P).
> 
> I never saw a case where the Usage Page was after the Usage. And I
> would lean towards Nicolas interpretation.
> However, Terry's point is valid too, and by re-reading the two
> paragraphs, one could argue that the "follows" of 6.2.2.7 could be
> applied when the Main item is processed as in 6.2.2.8.
> 
> So I am going to base my decision on the "reference" driver. How well
> behaves Windows with this particular keyboard?
> 
> If it behaves properly, then we better use the 6.2.2.8 version where
> the Usage Page is only appended when there is a Main item. This means
> we need to remember what size was the last Usage (and Min/Max), to
> know if we should concatenate the 2.
> 
> Note that for every change that involves the generic parser, I'd like
> a few tests added to `tests/test_keyboard.py in
> https://gitlab.freedesktop.org/libevdev/hid-tools
> Also note that the HID parser implementation in hid-tools follows the
> kernel, so we might need to adjust it there too if we want to add high
> level events. If you directly call `.call_input_event()` with raw
> events, it should be fine.

Thanks for the reply. I might get my hands on one of the faulty keyboards soon
so I'll be able to check windows' behaviour and test the patches.

Regards,
Nicolas


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 488 bytes --]