[RFC] HID: Use SET_REPORT request on control endpoint in hid-rmi for Acer Switch 3 and 5 cover keyboards

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The touchpad on the cover keyboard for the Acer Switch 3 and 5 does not
work as-is under Linux. Both devices have the same usb id for the cover
keyboard.

The kernel correctly assigns the hid-rmi driver to the device using usbhid
for transport.
Any attempts of hid-rmi to talk to the device using hid_hw_output_report
fail however as usbhid does not have a working urbout due to the lack of
any out endpoints.

Looking through Wireshark usbmon recordings from the Windows Synaptics
driver for this computer running inside of QEMU shows that it should be
using SET_REPORT requests instead.

The supplied patch replaces the hid_hw_output_report in hid-rmi with a
hid_hw_raw_request for this device, which is at least enough to enable
the kernel to get working multi-touch input.
Any feedback on how to integrate such a fix into the kernel in a more
preferred way would be much appreciated. (Hence this is sent as an RFC)

There are still further issues with the touchpad, such as occasional poor
responsiveness and the physical buttons being stuck once pressed, however
those issues do not seem related directly to this particular issue.

The problem has been reported previously in a variety of places:
https://www.spinics.net/lists/linux-input/msg58433.html
https://bugzilla.kernel.org/show_bug.cgi?id=95851
https://ubuntuforums.org/showthread.php?t=2403167
https://community.acer.com/en/discussion/542762/acer-switch-5-linux-mint-touchpad-not-working

Signed-off-by: Tobias Auerochs <tobi291019@xxxxxxxxx>
---
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index b6d93f4ad037..3fc369477d52 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -1083,6 +1083,7 @@
 #define USB_DEVICE_ID_SYNAPTICS_HD	0x0ac3
 #define USB_DEVICE_ID_SYNAPTICS_QUAD_HD	0x1ac3
 #define USB_DEVICE_ID_SYNAPTICS_TP_V103	0x5710
+#define USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5	0x81a7
 
 #define USB_VENDOR_ID_TEXAS_INSTRUMENTS	0x2047
 #define USB_DEVICE_ID_TEXAS_INSTRUMENTS_LENOVO_YOGA	0x0855
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index 953908f2267c..67b75665db37 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -158,6 +158,7 @@ static const struct hid_device_id hid_quirks[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SYNAPTICS, USB_DEVICE_ID_SYNAPTICS_LTS2), HID_QUIRK_NO_INIT_REPORTS },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SYNAPTICS, USB_DEVICE_ID_SYNAPTICS_QUAD_HD), HID_QUIRK_NO_INIT_REPORTS },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SYNAPTICS, USB_DEVICE_ID_SYNAPTICS_TP_V103), HID_QUIRK_NO_INIT_REPORTS },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SYNAPTICS, USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5), HID_QUIRK_RMI_OUTPUT_SET_REPORT },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_TOPMAX, USB_DEVICE_ID_TOPMAX_COBRAPAD), HID_QUIRK_BADPAD },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_TOUCHPACK, USB_DEVICE_ID_TOUCHPACK_RTS), HID_QUIRK_MULTI_INPUT },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_TPV, USB_DEVICE_ID_TPV_OPTICAL_TOUCHSCREEN_8882), HID_QUIRK_NOGET },
diff --git a/drivers/hid/hid-rmi.c b/drivers/hid/hid-rmi.c
index 9e33165250a3..50d7955e91b1 100644
--- a/drivers/hid/hid-rmi.c
+++ b/drivers/hid/hid-rmi.c
@@ -169,7 +169,18 @@ static int rmi_write_report(struct hid_device *hdev, u8 *report, int len)
 {
 	int ret;
 
-	ret = hid_hw_output_report(hdev, (void *)report, len);
+	if (hdev->quirks & HID_QUIRK_RMI_OUTPUT_SET_REPORT) {
+		/*
+		 * Talk to device by using SET_REPORT requests instead.
+		 * The report id is already in report[0],
+		 * so pass that to make usbhid not mess with it.
+		 */
+		ret = hid_hw_raw_request(hdev, report[0], report,
+				len, HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);
+	} else {
+		ret = hid_hw_output_report(hdev, (void *)report, len);
+	}
+
 	if (ret < 0) {
 		dev_err(&hdev->dev, "failed to write hid report (%d)\n", ret);
 		return ret;
diff --git a/include/linux/hid.h b/include/linux/hid.h
index f9707d1dcb58..b39a32c874f1 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -359,6 +359,7 @@ struct hid_item {
 #define HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP	BIT(18)
 #define HID_QUIRK_HAVE_SPECIAL_DRIVER		BIT(19)
 #define HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE	BIT(20)
+#define HID_QUIRK_RMI_OUTPUT_SET_REPORT		BIT(21)
 #define HID_QUIRK_FULLSPEED_INTERVAL		BIT(28)
 #define HID_QUIRK_NO_INIT_REPORTS		BIT(29)
 #define HID_QUIRK_NO_IGNORE			BIT(30)





[Index of Archives]     [Linux Media Devel]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Linux Wireless Networking]     [Linux Omap]

  Powered by Linux