Hi again!
On 2022-07-25 18:48, José Expósito wrote:
Hi everyone,
On Sun, Jul 24, 2022 at 01:48:49PM +0200, José Expósito wrote:
On Fri, 22 Jul 2022, Stefan Hansson wrote:
Hi!
Somewhere between Linux 5.17.6 and 5.18.11 the Huion tablet I have stopped
working properly. In GNOME Control Center it is identified as Huion New 1060
Plus, however that's a different tablet than the one I have. Mine is a Huion
Inspiroy H640, and it uses the hid_uclogic driver.
With Linux 5.17.6, the tablet works as expected with all the buttons being
detected and the stylus being usable. With 5.18.11, the buttons work fine but
the stylus does not work correctly. The first time I approach the tablet with
the stylus it works properly, i.e., the cursor on my screen moves around and
follows the stylus around the tablet as expected. It continues working like
this until I remove the stylus from the tablet. After I remove it from the
tablet, the cursor never gets controlled by the stylus again. I can see that
the tablet detects the stylus (it has a small indicator light), but the cursor
doesn't move when I approach the tablet again. To clarify, with Linux 5.17.6,
the cursor moves around just fine when I remove and then put it back to the
tablet, just as you would expected.
It may also be worth noting that it worked fine when I previously used it
around six months ago, although I'm not sure what version of Linux I was using
at that time (whatever Fedora shipped back then). I also tried reproducing it
with yesterday's linux-next and Linux 5.19.0-RC7, and the behaviour was the
same as 5.18.11. I am currently trying to bisect this, but it's not going very
fast as I currently only have access to a dual core laptop from 2014, so
building Linux takes a good while.
Thanks a lot for reporting the issue.
HUION and other non-Wacom tablets are handled by the UCLogic driver.
This driver is present in the kernel but its changes were deployed
and tested first in the DIGImend driver:
https://github.com/DIGImend/digimend-kernel-drivers
A while ago, I started including in the kernel the code present in
DIGImend. At this moment, 5.19.0-RC7 and DIGImend have the same code
(well, 5.19 has more features, but they don't affect your tablet).
I'm telling you this because it might be easier for you to bisect the
changes in the DIGImend driver as it builds way faster than the kernel.
Let me know if you need help bisecting it and I'll do my best to help
you.
Is this your device?
https://www.huion.com/pen_tablet/Inspiroy/H640P.html
Yes :)
It is affordable, so I ordered it. I don't have any HUION devices to
debug and this is a good excuse to buy one ;)
I'll let you know how it goes once I receive it.
The tablet arrived today and it is a bank holiday in Spain, so I had
some time to bisect the bug.
The first bad commit is 87562fcd1342 ("HID: input: remove the need for
HID_QUIRK_INVERT"):
https://lore.kernel.org/all/20220203143226.4023622-11-benjamin.tissoires@xxxxxxxxxx/
(CCing the folks whose email is in the patch tags)
I reverted the patch on hid/for-next and, after fixing a tiny conflict,
I can confirm that the tablet works again as expected.
Thanks for looking into this! Bisecting has been slow on my end
unfortunately. I built today's linux-next (20220726) with your proposed
patch below and my drawing tablet curiously still does not work as
expected. The stylus works a couple of times, but eventually stops
working (unlike prior where it always seemed to only work once). Do I
need both your revert and this diff for it to work properly?
Also, do you know whether the revert be backported to stable 5.18?
I'd need to investigate a bit more over the weekend, but I think that
all HUION tablets with the latest firmware (internally, v2) are
affected.
Those tablets do not set the inrange bit (UCLOGIC_PARAMS_PEN_INRANGE_NONE).
The driver sets it and uses a timer to remove it.
See drivers/hid/hid-uclogic-core.c, function uclogic_raw_event_pen().
However, at least the Huion Inspiroy H640, sends a 0x00 byte when the
tool is removed, making it possible to fix it in the driver [1].
Unfortunately, the affected code path is used by many tablets and I
can not test them, so I'd prefer to hear Benjamin's opinion and see if
this should be fixed in hid-input rather than in the driver before
sending a fix.
Best wishes,
José Expósito
[1] Diff of a possible fix:
diff --git a/drivers/hid/hid-uclogic-core.c b/drivers/hid/hid-uclogic-core.c
index 47a17375c7fc..bdcbbd57d0fc 100644
--- a/drivers/hid/hid-uclogic-core.c
+++ b/drivers/hid/hid-uclogic-core.c
@@ -316,8 +316,11 @@ static int uclogic_raw_event_pen(struct uclogic_drvdata *drvdata,
}
/* If we need to emulate in-range detection */
if (pen->inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE) {
/* Set in-range bit */
- data[1] |= 0x40;
+ if (data[1])
+ data[1] |= 0x40;
+
/* (Re-)start in-range timeout */
mod_timer(&drvdata->inrange_timer,
jiffies + msecs_to_jiffies(100));
Regards,
Stefan Hansson
