Hi Jonathan, On 1/11/24 00:42, Jonathan Denose wrote: > Dmitry, > > Sorry I forgot to reply all, so I'm resending my other email. > > On Tue, Jan 9, 2024 at 1:28 PM Dmitry Torokhov > <dmitry.torokhov@xxxxxxxxx> wrote: >> >> Hi Jonathan, >> >> On Mon, Nov 27, 2023 at 10:38:57AM -0600, Jonathan Denose wrote: >>> Hi Dmitry >>> >>> On Fri, Nov 24, 2023 at 10:45 PM Dmitry Torokhov >>> <dmitry.torokhov@xxxxxxxxx> wrote: >>>> >>>> Hi Jonathan, >>>> >>>> On Mon, Sep 25, 2023 at 04:33:20PM -0500, Jonathan Denose wrote: >>>>> The ThinkPad T14 Gen 1 touchpad works fine except that clicking >>>>> and dragging by tapping the touchpad or depressing the touchpad >>>>> do not work. Disabling PNP for controller setting discovery enables >>>>> click and drag without negatively impacting other touchpad features. >>>> >>>> I would like to understand more on how enabling PnP discovery for i8042 >>>> affects the touchpad. Do you see it using different interrupt or IO >>>> ports? What protocol does the touchpad use with/without PnP? If the >>>> protocol is the same, do you see difference in the ranges (pressure, >>>> etc) reported by the device? >>>> >>>> Thanks. >>>> >>>> -- >>>> Dmitry >>> >>> Without PnP discovery the touchpad is using the SynPS/2 protocol, with >>> PnP discovery, the touchpad is using the rmi4 protocol. Since the >>> protocols are different, so are the ranges but let me know if you >>> still want to see them. >> >> Thank you for this information. So it is not PnP discovery that appears >> harmful in your case, but rather that legacy PS/2 mode appears to be >> working better than RMI4 for the device in question. >> >> I will note that the original enablement of RMI4 for T14 was done by >> Hans in [1]. Later T14 with AMD were added to the list of devices that >> should use RMI4 [2], however this was reverted in [3]. >> >> Could you please tell me what exact device you are dealing with? What's >> it ACPI ID? >> >> [1] https://lore.kernel.org/all/20201005114919.371592-1-hdegoede@xxxxxxxxxx/ >> [2] https://lore.kernel.org/r/20220318113949.32722-1-snafu109@xxxxxxxxx >> [3] https://lore.kernel.org/r/20220920193936.8709-1-markpearson@xxxxxxxxxx >> >> Thanks. >> >> -- >> Dmitry > > Thanks for your reply! > > I'm not 100% sure which of these is the ACPI ID, but from `udevadm > info -e` there's: > N: Name="Synaptics TM3471-020" > P: Phys=rmi4-00/input0 To get the ACPI ID you need to run e.g. :`` cat /sys/bus/serio/devices/serio1/firmware_id After reading the original bug report again I take back my Reviewed-by and I'm tending towards a nack for this. Jonathan upon re-reading things I think that your problem is more a case of user space mis-configuration then a kernel problem. You mention both tap-n-drag not working as well as click+drag not working. tap-n-drag is purely done in userspace and typically only works if tap-to-click is enabled in the touchpad configuration of your desktop environment. Click + drag requires you to use the bottom of the touchpad (the only part which actually clicks) as if there still were 2 physical buttons there and then click the touchpad down with 1 finger till it clicks and then drags with another finger (you can click+drag with one finger but the force required to keep the touchpad clicked down while dragging makes this uncomfortable to do). This will likely also only work if the mouse click emulation mode is set to "area" and not "fingers" with "fingers" being the default now. In GNOME you can configure the "click emulation mode" in the "tweaks" tools under "mouse & touchpad" (and tap to click is in the normal settings menu / control panel). If you have the click emulations set to fingers and then do the click with 1 finger + drag with another finger thing, I think the drag will turn into a right button drag instead of a left button drag which is likely why this is not working. You can check which mode you are in by seeing how you right click. If you right-click by pressing down in the right bottom corner of the touchpad then your userspace (libinput) config is set to areas, if you can right click anywhere by pressing down with 2 fingers at once then your click emulation is in fingers mode and this is likely why click-n-drag is not working. I have just dug up my T14 gen1 (Intel) and updated it to kernel 6.6.11 to rule out kernel regressions. And both click-n-drag and tap-n-drag (double-tap then drag) both work fine there with a touchpad with an ACPI id of LEN2068 as shown by cat /sys/bus/serio/devices/serio1/firmware_id (with the Desktop Environment configured for bottom area click emulation and tap-to-click enabled) As for why changing things back to synps2 works, I don't know. One guess is that you already configured the touchpad behavior of your desktop environment to your liking in the past and your desktop environment has remembered this only for the input device-name which is used in SynPS/2 mode and the different input device-name in RMI4 mode in new (new-ish) kernels causes the desktop environment to use default settings which are typically "fingers" click emulation and tap-to-click disabled. This can e.g. also happen if you have moved your disk (contents) over from an older machine. IIRC the SynPS/2 driver always used the same input device-name where as with RMI4 the name is tied to the actual laptop model. Regards, Hans
