On 04/10/2017 11:38 AM, Dmitry Torokhov wrote:
On Mon, Apr 10, 2017 at 03:18:03PM +0200, Jiri Kosina wrote:
[ a couple more people from "the other regression thread" added to CC ]
On Mon, 10 Apr 2017, Gabriele Mazzotta wrote:
Hi,
I'm having troubles with hid-rmi using 4.11-rc6. I'm getting some
"rmi_hid_read_block: timeout elapsed" errors and ultimately the
crash you can see at the end of this mail. I will reply to this
mail with a full log that shows all the errors.
The problem seems to be caused by commit 279967a65b320d174a507498ae
("HID: rmi: Handle all Synaptics touchpads using hid-rmi").
My laptop has a Synaptics touchpad and a Synaptics touchscreen.
Because of that commit, hid-rmi is used for both the devices, while
it has always been used only for the touchpad. Needless to say that
the touchscreen no longer works.
If I revert that commit, everything goes back to normal.
Alright, given this is a second regression cause by this switch, I suggest
to revert this one for 4.11 still, and work on fixing this properly for
4.12.
If noone raises any objections (a few more people added to Cc), I'll queue
a 4.11-rc revert tomorrow.
Yes, we also have this:
https://bugzilla.kernel.org/show_bug.cgi?id=195287
I suspect that the issue might be that both of these touchscreens have
the HID_GD_POINTER usage defined in their HID report descriptor. This
might be because the firmware is configured to support pens. It looks
like the Asus T302CA from the bug does have a pen and the XPS13 9333 may
simply have firmware which has pen support enabled. The HID_GD_POINTER
usage is used in hid-core to differentiate between touchpads and
touchscreens. So if a touchscreen has HID_GD_POINTER defined then
hid-core will bind hid-rmi to it. None, of my test systems have pen
support so I did not anticipate this.
Also, the reason why we can't just support touchscreens using hid-rmi is
because the firmware for HID touchscreens lacks the functionality of
reporting the attention data (finger positions) in a single report. It
ends up being less efficient to run HID touchscreens in RMI mode.
so reverting seems prudent at this time.
Yes, I agree we should revert the commit. There simply isn't enough time
to come up with and test a new method for differentiating touchpads and
touchscreens before 4.11 is released.
Andrew
Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
