FWIW, I found the issue: the hid-uclogic driver is emitting input data
behind hid-input, and the state between the 2 is desynchronized.
The following patch seems to be working (with the Huion v1 protocol I
have here that I have tweaked to resemble a v2):
---
From aeedd318e6cb4dbee551f67616302cc7c4308c58 Mon Sep 17 00:00:00 2001
From: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Date: Thu, 18 Aug 2022 15:09:25 +0200
Subject: [PATCH] Fix uclogic
---
drivers/hid/hid-input.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index c6b27aab9041..a3e2397bb3a7 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1530,7 +1530,10 @@ void hidinput_hid_event(struct hid_device *hid,
struct hid_field *field, struct
* assume ours
*/
if (!report->tool)
- hid_report_set_tool(report, input, usage->code);
+ report->tool = usage->code;
+
+ /* drivers may have changed the value behind our back,
resend it */
+ hid_report_set_tool(report, input, report->tool);
} else {
hid_report_release_tool(report, input, usage->code);
}
What branch should this be applied on top of?
