DIGImend cooperation

[spbnick]

Hello,

I'm the developer behind the DIGImend project and I'm glad to see that someone develops another tablet driver for Linux.

Please feel free to lift whatever code pieces you need from the digimend-kernel-drivers (perhaps the hid-rebind part?). I will also be glad to accept your contributions, of course.

Nick

[aidyw]

Thanks Nicolai, interesting.

As a different developer I wonder if you have any experience along the same lines as myself. Before I proceed, I do want to be sure Anton does not jump on this, as I am quite sure it does not relate to his issues. However, I have a working driver that I did much of the coding on, yet I still have occasional problems. Its a strange one:

Sometimes the pressure input from the tablet gets screwed up. It works as long as the pressure does not get to large. When this problem occurs the 2 bytes (pen pressure) from the input subsystem, become corrupted. It makes no difference if I unload the module and reload, it makes no difference if I restart the OS. However it clears the problem every single time if I shut down my machine, turn off the main power to the motherboard and then reboot. Once I have done this, the driver works no issues and I can clearly see that the data from the input subsystem is clean.

Its as though the USB hardware on my motherboard needs to be rebooted. Perhaps its a microcode issue?? I’m putting up with it as I know the cure works without fail. Weird. Any ideas.

Aidan

On 16 Mar 2016, at 21:04, Nikolai Kondrashov notifications@github.com wrote:

Hello,

I'm the developer behind the DIGImend project http://digimend.github.io/ and I'm glad to see that someone develops another tablet driver for Linux.

Please feel free to lift whatever code pieces you need from the digimend-kernel-drivers https://github.com/DIGImend/digimend-kernel-drivers (perhaps the hid-rebind part?). I will also be glad to accept your contributions, of course.

Nick

— You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub https://github.com/aidyw/bosto-2g-linux-kernel-module/issues/6

[spbnick]

Well, yeah, this looks like a hardware issue. I've seen a number of them, but not quite the same as you have.

Do you have any more tablets of the same model? If yes, do they work the same? I assume just reconnecting the tablet (without rebooting the machine) doesn't work? What if you wait a few more seconds after disconnecting and before reconnecting it, perhaps letting the capacitors inside the tablet discharge? I would rather suspect a faulty tablet or cable than the host USB.

Have you checked the raw USB data coming from the tablet, perhaps with the help of Wireshark or /sys/kernel/debug/hid tree, or usbhid-dump? Does it show the same data?

[lesliev]

On 17 March 2016 at 09:48, Nikolai Kondrashov notifications@github.com wrote:

Well, yeah, this looks like a hardware issue. I've seen a number of them, but not quite the same as you have.

Do you have any more tablets of the same model? If yes, do they work the same? I assume just reconnecting the tablet (without rebooting the machine) doesn't work? What if you wait a few more seconds after disconnecting and before reconnecting it, perhaps letting the capacitors inside the tablet discharge? I would rather suspect a faulty tablet or cable than the host USB.

Have you checked the raw USB data coming from the tablet, perhaps with the help of Wireshark or /sys/kernel/debug/hid tree, or usbhid-dump? Does it show the same data?

I've not seen this issue on my tablet Aidan, though I do have the 14WA model.

[spbnick]

I'd suspect that Aidan's pen either produces stronger signal which confuses the sensing electronics or breaks something inside itself from higher pressure. Although the latter is less likely given the symptoms.

Can you try to see to what maximum reported pressure number both of your tablets can get? And if Aidan's gets higher or develops the quirk right at the top of the range?

[aidyw]

Thanks, I appreciate the effort, but I must say I can’t agree with the methodology to debug this. As I stated during times when my pressure input works, the byte stream from the tablet is clear and reliable. It is well within any limits that might cause an overflow condition. Yet more importantly, the resolution involves powering down the computer motherboard. Well this very definitely points to something related to the USB subsystem in Linux and not the Tablet. In this regard I am stumped.

Maybe it is not worth pursuing further. If I am alone with this problem, then I deal with it alone. Perhaps in fact I am alone in using the driver anyway :) I suspect there are not too many others making use of it.

But as I like to do occasionally just for everyones pleasure I attach my latest artwork. Created with the master branch on my 22HD. I mean after all this is why I coded this thing in the first place. A little watercolour effect and dreaming of scuba diving. Dream on guys.

All the best and regards Aidan

On 16 Mar 2016, at 22:21, Nikolai Kondrashov notifications@github.com wrote:

I'd suspect that Aidan's pen either produces stronger signal which confuses the sensing electronics or breaks something inside itself from higher pressure. Although the latter is less likely given the symptoms.

Can you try to see to what maximum reported pressure number both of your tablets can get? And if Aidan's gets higher or develops the quirk right at the top of the range?

— You are receiving this because you commented. Reply to this email directly or view it on GitHub https://github.com/aidyw/bosto-2g-linux-kernel-module/issues/6#issuecomment-197554290

[spbnick]

Sure! You're welcome, and I can be wrong (would suggest trying on another PC in that case, of course).

Nice artwork :) I half expected to see Discworld on top of that turtle :)