[PATCH v3 0/7] HID: lenovo: Mute LED handling fixes and improvements

[PATCH v3 0/7] HID: lenovo: Mute LED handling fixes and improvements

[Hans de Goede]

Hi All,

Here is v3 of my series with mute LED handling fixes and improvements
for the hid-lenovo driver.

v3 addresses the review-remarks from Marek Behún, thank you for all the
reviews Marek.

See the individual patches for detailed per patch changelogs.

Regards,

Hans


Hans de Goede (7):
  HID: lenovo: Use brightness_set_blocking callback for setting LEDs
    brightness
  HID: lenovo: Fix lenovo_led_set_tp10ubkbd() error handling
  HID: lenovo: Check hid_get_drvdata() returns non NULL in
    lenovo_event()
  HID: lenovo: Remove lenovo_led_brightness_get()
  HID: lenovo: Set LEDs max_brightness value
  HID: lenovo: Map mic-mute button to KEY_F20 instead of KEY_MICMUTE
  HID: lenovo: Set default_triggers for the mute and micmute LEDs

 drivers/hid/hid-lenovo.c | 69 ++++++++++++++++++++++------------------
 1 file changed, 38 insertions(+), 31 deletions(-)

-- 
2.30.1

[PATCH v3 1/7] HID: lenovo: Use brightness_set_blocking callback for setting LEDs brightness

[Hans de Goede]

The lenovo_led_brightness_set function may sleep, so we should have the
the led_class_dev's brightness_set_blocking callback point to it, rather
then the regular brightness_set callback.

When toggled through sysfs this is not a problem, but the brightness_set
callback may be called from atomic context when using LED-triggers.

Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support")
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-lenovo.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index c6c8e20f3e8d..4dc5e5f932ed 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -777,7 +777,7 @@ static enum led_brightness lenovo_led_brightness_get(
 				: LED_OFF;
 }
 
-static void lenovo_led_brightness_set(struct led_classdev *led_cdev,
+static int lenovo_led_brightness_set(struct led_classdev *led_cdev,
 			enum led_brightness value)
 {
 	struct device *dev = led_cdev->dev->parent;
@@ -802,6 +802,8 @@ static void lenovo_led_brightness_set(struct led_classdev *led_cdev,
 		lenovo_led_set_tp10ubkbd(hdev, tp10ubkbd_led[led_nr], value);
 		break;
 	}
+
+	return 0;
 }
 
 static int lenovo_register_leds(struct hid_device *hdev)
@@ -822,7 +824,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 
 	data->led_mute.name = name_mute;
 	data->led_mute.brightness_get = lenovo_led_brightness_get;
-	data->led_mute.brightness_set = lenovo_led_brightness_set;
+	data->led_mute.brightness_set_blocking = lenovo_led_brightness_set;
 	data->led_mute.dev = &hdev->dev;
 	ret = led_classdev_register(&hdev->dev, &data->led_mute);
 	if (ret < 0)
@@ -830,7 +832,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 
 	data->led_micmute.name = name_micm;
 	data->led_micmute.brightness_get = lenovo_led_brightness_get;
-	data->led_micmute.brightness_set = lenovo_led_brightness_set;
+	data->led_micmute.brightness_set_blocking = lenovo_led_brightness_set;
 	data->led_micmute.dev = &hdev->dev;
 	ret = led_classdev_register(&hdev->dev, &data->led_micmute);
 	if (ret < 0) {
-- 
2.30.1

[PATCH v3 2/7] HID: lenovo: Fix lenovo_led_set_tp10ubkbd() error handling

[Hans de Goede]

Fix the following issues with lenovo_led_set_tp10ubkbd() error handling:

1. On success hid_hw_raw_request() returns the number of bytes sent.
   So we should check for (ret != 3) rather then for (ret != 0).

2. Actually propagate errors to the caller.

3. Since the LEDs are part of an USB keyboard-dock the mute LEDs can go
   away at any time. Don't log an error when ret == -ENODEV and set the
   LED_HW_PLUGGABLE flag to avoid errors getting logged when the USB gets
   disconnected.

Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v3:
- Return -EIO when hid_hw_raw_request() returns a value != 3 and >= 0

Changes in v2:
- Rewrite to fix a bunch of other error-handling issues too
---
 drivers/hid/hid-lenovo.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index 4dc5e5f932ed..ee175ab54281 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -62,8 +62,8 @@ struct lenovo_drvdata {
 #define TP10UBKBD_LED_OFF		1
 #define TP10UBKBD_LED_ON		2
 
-static void lenovo_led_set_tp10ubkbd(struct hid_device *hdev, u8 led_code,
-				     enum led_brightness value)
+static int lenovo_led_set_tp10ubkbd(struct hid_device *hdev, u8 led_code,
+				    enum led_brightness value)
 {
 	struct lenovo_drvdata *data = hid_get_drvdata(hdev);
 	int ret;
@@ -75,10 +75,18 @@ static void lenovo_led_set_tp10ubkbd(struct hid_device *hdev, u8 led_code,
 	data->led_report[2] = value ? TP10UBKBD_LED_ON : TP10UBKBD_LED_OFF;
 	ret = hid_hw_raw_request(hdev, data->led_report[0], data->led_report, 3,
 				 HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);
-	if (ret)
-		hid_err(hdev, "Set LED output report error: %d\n", ret);
+	if (ret != 3) {
+		if (ret != -ENODEV)
+			hid_err(hdev, "Set LED output report error: %d\n", ret);
+
+		ret = ret < 0 ? ret : -EIO;
+	} else {
+		ret = 0;
+	}
 
 	mutex_unlock(&data->led_report_mutex);
+
+	return ret;
 }
 
 static void lenovo_tp10ubkbd_sync_fn_lock(struct work_struct *work)
@@ -349,7 +357,7 @@ static ssize_t attr_fn_lock_store(struct device *dev,
 {
 	struct hid_device *hdev = to_hid_device(dev);
 	struct lenovo_drvdata *data = hid_get_drvdata(hdev);
-	int value;
+	int value, ret;
 
 	if (kstrtoint(buf, 10, &value))
 		return -EINVAL;
@@ -364,7 +372,9 @@ static ssize_t attr_fn_lock_store(struct device *dev,
 		lenovo_features_set_cptkbd(hdev);
 		break;
 	case USB_DEVICE_ID_LENOVO_TP10UBKBD:
-		lenovo_led_set_tp10ubkbd(hdev, TP10UBKBD_FN_LOCK_LED, value);
+		ret = lenovo_led_set_tp10ubkbd(hdev, TP10UBKBD_FN_LOCK_LED, value);
+		if (ret)
+			return ret;
 		break;
 	}
 
@@ -785,6 +795,7 @@ static int lenovo_led_brightness_set(struct led_classdev *led_cdev,
 	struct lenovo_drvdata *data_pointer = hid_get_drvdata(hdev);
 	u8 tp10ubkbd_led[] = { TP10UBKBD_MUTE_LED, TP10UBKBD_MICMUTE_LED };
 	int led_nr = 0;
+	int ret = 0;
 
 	if (led_cdev == &data_pointer->led_micmute)
 		led_nr = 1;
@@ -799,11 +810,11 @@ static int lenovo_led_brightness_set(struct led_classdev *led_cdev,
 		lenovo_led_set_tpkbd(hdev);
 		break;
 	case USB_DEVICE_ID_LENOVO_TP10UBKBD:
-		lenovo_led_set_tp10ubkbd(hdev, tp10ubkbd_led[led_nr], value);
+		ret = lenovo_led_set_tp10ubkbd(hdev, tp10ubkbd_led[led_nr], value);
 		break;
 	}
 
-	return 0;
+	return ret;
 }
 
 static int lenovo_register_leds(struct hid_device *hdev)
@@ -825,6 +836,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 	data->led_mute.name = name_mute;
 	data->led_mute.brightness_get = lenovo_led_brightness_get;
 	data->led_mute.brightness_set_blocking = lenovo_led_brightness_set;
+	data->led_mute.flags = LED_HW_PLUGGABLE;
 	data->led_mute.dev = &hdev->dev;
 	ret = led_classdev_register(&hdev->dev, &data->led_mute);
 	if (ret < 0)
@@ -833,6 +845,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 	data->led_micmute.name = name_micm;
 	data->led_micmute.brightness_get = lenovo_led_brightness_get;
 	data->led_micmute.brightness_set_blocking = lenovo_led_brightness_set;
+	data->led_micmute.flags = LED_HW_PLUGGABLE;
 	data->led_micmute.dev = &hdev->dev;
 	ret = led_classdev_register(&hdev->dev, &data->led_micmute);
 	if (ret < 0) {
-- 
2.30.1

Re: [PATCH v3 2/7] HID: lenovo: Fix lenovo_led_set_tp10ubkbd() error handling

[Marek Behún]

Reviewed-by: Marek Behún <kabel@kernel.org>

[PATCH v3 3/7] HID: lenovo: Check hid_get_drvdata() returns non NULL in lenovo_event()

[Hans de Goede]

The HID lenovo probe function only attaches drvdata to one of the
USB interfaces, but lenovo_event() will get called for all USB interfaces
to which hid-lenovo is bound.

This allows a malicious device to fake being a device handled by
hid-lenovo, which generates events for which lenovo_event() has
special handling (and thus dereferences hid_get_drvdata()) on another
interface triggering a NULL pointer exception.

Add a check for hid_get_drvdata() returning NULL, avoiding this
possible NULL pointer exception.

Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support")
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-lenovo.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index ee175ab54281..b2596ed37880 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -508,6 +508,9 @@ static int lenovo_event_cptkbd(struct hid_device *hdev,
 static int lenovo_event(struct hid_device *hdev, struct hid_field *field,
 		struct hid_usage *usage, __s32 value)
 {
+	if (!hid_get_drvdata(hdev))
+		return 0;
+
 	switch (hdev->product) {
 	case USB_DEVICE_ID_LENOVO_CUSBKBD:
 	case USB_DEVICE_ID_LENOVO_CBTKBD:
-- 
2.30.1

[PATCH v3 4/7] HID: lenovo: Remove lenovo_led_brightness_get()

[Hans de Goede]

The led_classdev already contains a cached value of the last set
brightness, the brightness_get callback is only meant for LED drivers
which can read back the actual / current brightness from the hardware.

Since lenovo_led_brightness_get() just returns the last set value
it does not add any functionality, so we can just remove it.

Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
- New patch in v2 of this patch-set
---
 drivers/hid/hid-lenovo.c | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index b2596ed37880..1b8dd85ceb05 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -774,22 +774,6 @@ static void lenovo_led_set_tpkbd(struct hid_device *hdev)
 	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
 }
 
-static enum led_brightness lenovo_led_brightness_get(
-			struct led_classdev *led_cdev)
-{
-	struct device *dev = led_cdev->dev->parent;
-	struct hid_device *hdev = to_hid_device(dev);
-	struct lenovo_drvdata *data_pointer = hid_get_drvdata(hdev);
-	int led_nr = 0;
-
-	if (led_cdev == &data_pointer->led_micmute)
-		led_nr = 1;
-
-	return data_pointer->led_state & (1 << led_nr)
-				? LED_FULL
-				: LED_OFF;
-}
-
 static int lenovo_led_brightness_set(struct led_classdev *led_cdev,
 			enum led_brightness value)
 {
@@ -837,7 +821,6 @@ static int lenovo_register_leds(struct hid_device *hdev)
 	snprintf(name_micm, name_sz, "%s:amber:micmute", dev_name(&hdev->dev));
 
 	data->led_mute.name = name_mute;
-	data->led_mute.brightness_get = lenovo_led_brightness_get;
 	data->led_mute.brightness_set_blocking = lenovo_led_brightness_set;
 	data->led_mute.flags = LED_HW_PLUGGABLE;
 	data->led_mute.dev = &hdev->dev;
@@ -846,7 +829,6 @@ static int lenovo_register_leds(struct hid_device *hdev)
 		return ret;
 
 	data->led_micmute.name = name_micm;
-	data->led_micmute.brightness_get = lenovo_led_brightness_get;
 	data->led_micmute.brightness_set_blocking = lenovo_led_brightness_set;
 	data->led_micmute.flags = LED_HW_PLUGGABLE;
 	data->led_micmute.dev = &hdev->dev;
-- 
2.30.1

Re: [PATCH v3 4/7] HID: lenovo: Remove lenovo_led_brightness_get()

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 596 bytes --]

On Sun 2021-02-21 12:20:02, Hans de Goede wrote:
> The led_classdev already contains a cached value of the last set
> brightness, the brightness_get callback is only meant for LED drivers
> which can read back the actual / current brightness from the hardware.
> 
> Since lenovo_led_brightness_get() just returns the last set value
> it does not add any functionality, so we can just remove it.
> 
> Reviewed-by: Marek Behún <kabel@kernel.org>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
http://www.livejournal.com/~pavelmachek

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[PATCH v3 5/7] HID: lenovo: Set LEDs max_brightness value

[Hans de Goede]

The LEDs can only by turned on/off, so max_brightness should be set to 1.
Without this the max_brightness sysfs-attribute will report 255 which is
wrong.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v3:
- Use 1 instead of LED_ON

Changes in v2:
- New patch in v2 of this patch-set
---
 drivers/hid/hid-lenovo.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index 1b8dd85ceb05..668762663f69 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -822,6 +822,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 
 	data->led_mute.name = name_mute;
 	data->led_mute.brightness_set_blocking = lenovo_led_brightness_set;
+	data->led_mute.max_brightness = 1;
 	data->led_mute.flags = LED_HW_PLUGGABLE;
 	data->led_mute.dev = &hdev->dev;
 	ret = led_classdev_register(&hdev->dev, &data->led_mute);
@@ -830,6 +831,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 
 	data->led_micmute.name = name_micm;
 	data->led_micmute.brightness_set_blocking = lenovo_led_brightness_set;
+	data->led_micmute.max_brightness = 1;
 	data->led_micmute.flags = LED_HW_PLUGGABLE;
 	data->led_micmute.dev = &hdev->dev;
 	ret = led_classdev_register(&hdev->dev, &data->led_micmute);
-- 
2.30.1

Re: [PATCH v3 5/7] HID: lenovo: Set LEDs max_brightness value

[Marek Behún]

Reviewed-by: Marek Behún <kabel@kernel.org>

Re: [PATCH v3 5/7] HID: lenovo: Set LEDs max_brightness value

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 358 bytes --]

On Sun 2021-02-21 12:20:03, Hans de Goede wrote:
> The LEDs can only by turned on/off, so max_brightness should be set to 1.
> Without this the max_brightness sysfs-attribute will report 255 which is
> wrong.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
http://www.livejournal.com/~pavelmachek

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[PATCH v3 6/7] HID: lenovo: Map mic-mute button to KEY_F20 instead of KEY_MICMUTE

[Hans de Goede]

Mapping the mic-mute button to KEY_MICMUTE is technically correct but
KEY_MICMUTE translates to a scancode of 256 (248 + 8) under X,
which does not fit in 8 bits, so it does not work.

Because of this userspace is expecting KEY_F20 instead,
theoretically KEY_MICMUTE should work under Wayland but even
there it does not work, because the desktop-environment is
listening only for KEY_F20 and not for KEY_MICMUTE.

Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-lenovo.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index 668762663f69..2cf89b880ac5 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -33,6 +33,9 @@
 
 #include "hid-ids.h"
 
+/* Userspace expects F20 for mic-mute KEY_MICMUTE does not work */
+#define LENOVO_KEY_MICMUTE KEY_F20
+
 struct lenovo_drvdata {
 	u8 led_report[3]; /* Must be first for proper alignment */
 	int led_state;
@@ -134,7 +137,7 @@ static int lenovo_input_mapping_tpkbd(struct hid_device *hdev,
 	if (usage->hid == (HID_UP_BUTTON | 0x0010)) {
 		/* This sub-device contains trackpoint, mark it */
 		hid_set_drvdata(hdev, (void *)1);
-		map_key_clear(KEY_MICMUTE);
+		map_key_clear(LENOVO_KEY_MICMUTE);
 		return 1;
 	}
 	return 0;
@@ -149,7 +152,7 @@ static int lenovo_input_mapping_cptkbd(struct hid_device *hdev,
 	    (usage->hid & HID_USAGE_PAGE) == HID_UP_LNVENDOR) {
 		switch (usage->hid & HID_USAGE) {
 		case 0x00f1: /* Fn-F4: Mic mute */
-			map_key_clear(KEY_MICMUTE);
+			map_key_clear(LENOVO_KEY_MICMUTE);
 			return 1;
 		case 0x00f2: /* Fn-F5: Brightness down */
 			map_key_clear(KEY_BRIGHTNESSDOWN);
@@ -239,7 +242,7 @@ static int lenovo_input_mapping_tp10_ultrabook_kbd(struct hid_device *hdev,
 			map_key_clear(KEY_FN_ESC);
 			return 1;
 		case 9: /* Fn-F4: Mic mute */
-			map_key_clear(KEY_MICMUTE);
+			map_key_clear(LENOVO_KEY_MICMUTE);
 			return 1;
 		case 10: /* Fn-F7: Control panel */
 			map_key_clear(KEY_CONFIG);
-- 
2.30.1

Re: [PATCH v3 6/7] HID: lenovo: Map mic-mute button to KEY_F20 instead of KEY_MICMUTE

[Marek Behún]

Reviewed-by: Marek Behún <kabel@kernel.org>

[PATCH v3 7/7] HID: lenovo: Set default_triggers for the mute and micmute LEDs

[Hans de Goede]

The mute and mic-mute LEDs should be automatically turned on/off based
on the audio-card's mixer settings.

Add the standardized default-trigger names for this, so that the alsa
code can turn the LEDs on/off as appropriate (on supported audio cards).

This brings the mute/mic-mute LED support inline with the thinkpad_acpi
support for the same LEDs in keyboards directly connected to the
laptop's embedded-controller.

Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-lenovo.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
index 2cf89b880ac5..2287142116b9 100644
--- a/drivers/hid/hid-lenovo.c
+++ b/drivers/hid/hid-lenovo.c
@@ -824,6 +824,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 	snprintf(name_micm, name_sz, "%s:amber:micmute", dev_name(&hdev->dev));
 
 	data->led_mute.name = name_mute;
+	data->led_mute.default_trigger = "audio-mute";
 	data->led_mute.brightness_set_blocking = lenovo_led_brightness_set;
 	data->led_mute.max_brightness = 1;
 	data->led_mute.flags = LED_HW_PLUGGABLE;
@@ -833,6 +834,7 @@ static int lenovo_register_leds(struct hid_device *hdev)
 		return ret;
 
 	data->led_micmute.name = name_micm;
+	data->led_micmute.default_trigger = "audio-micmute";
 	data->led_micmute.brightness_set_blocking = lenovo_led_brightness_set;
 	data->led_micmute.max_brightness = 1;
 	data->led_micmute.flags = LED_HW_PLUGGABLE;
-- 
2.30.1

Re: [PATCH v3 7/7] HID: lenovo: Set default_triggers for the mute and micmute LEDs

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 690 bytes --]

On Sun 2021-02-21 12:20:05, Hans de Goede wrote:
> The mute and mic-mute LEDs should be automatically turned on/off based
> on the audio-card's mixer settings.
> 
> Add the standardized default-trigger names for this, so that the alsa
> code can turn the LEDs on/off as appropriate (on supported audio cards).
> 
> This brings the mute/mic-mute LED support inline with the thinkpad_acpi
> support for the same LEDs in keyboards directly connected to the
> laptop's embedded-controller.
> 
> Reviewed-by: Marek Behún <kabel@kernel.org>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
http://www.livejournal.com/~pavelmachek

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