Re: [PATCH v4] Input: Add driver for PixArt PS/2 touchpad

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Oct 01, 2024 at 11:21:10AM +0200, Benjamin Tissoires wrote:
> On Oct 01 2024, Dmitry Torokhov wrote:
> > On Tue, Oct 01, 2024 at 01:53:44AM -0700, Dmitry Torokhov wrote:
> > > On Mon, Sep 30, 2024 at 05:59:01PM +0200, Benjamin Tissoires wrote:
> > > > Hi,
> > > > 
> > > > On Jul 04 2024, Binbin Zhou wrote:
> > > > > This patch introduces a driver for the PixArt PS/2 touchpad, which
> > > > > supports both clickpad and touchpad types.
> > > > > 
> > > > > At the same time, we extended the single data packet length to 16,
> > > > > because according to the current PixArt hardware and FW design, we need
> > > > > 11 bytes/15 bytes to represent the complete three-finger/four-finger data.
> > > > > 
> > > > > Co-developed-by: Jon Xie <jon_xie@pixart.com>
> > > > > Signed-off-by: Jon Xie <jon_xie@pixart.com>
> > > > > Co-developed-by: Jay Lee <jay_lee@pixart.com>
> > > > > Signed-off-by: Jay Lee <jay_lee@pixart.com>
> > > > > Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> > > > 
> > > > It looks like this new driver made in v6.12-rc1 but is already breaking
> > > > other touchpads in fedora:
> > > > 
> > > > https://bugzilla.redhat.com/show_bug.cgi?id=2314756
> > > > 
> > > > The reported touchpads used to work properly but are now directed to use
> > > > the PixArt PS2 driver instead of the old one (I would say it should be
> > > > using Synaptics).
> > > > 
> > > > I haven't touched PS/2 in a long time, so it's going to be hard to
> > > > pinpoint the error from my side, but it seems that the new driver is a
> > > > little bit too greedy.
> > > 
> > > OK, I gonna revert it and hope PixArt folks will figure out less greedy
> > > probing sequence (or maybe we need to push it down a few sports).
> > 
> > Although, as I am trying to read the referenced bug, one of the
> > reporters are saying that they touchpad is USB:
> > 
> > SysFS ID: /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0
> > ysFS BusID: 3-3:1.0
> > Hardware Class: unknown
> > Model: "Synaptics Unclassified device"
> > Hotplug: USB
> > Vendor: usb 0x06cb "Synaptics, Inc."
> 
> I guess this must be the fingerprint reader or some other synaptics
> device.
> 
> In the 6.11 logs (now publicly available), we can see:
> [    1.601507] psmouse serio1: trackpoint: Elan TrackPoint firmware: 0x92, buttons: 3/3
> [    1.614026] input: TPPS/2 Elan TrackPoint as /devices/platform/i8042/serio1/input/input5
> ...
> [    2.286700] input: ELAN0672:00 04F3:3187 Mouse as /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-0/i2c-ELAN0672:00/0018:04F3:3187.0002/input/input7
> [    2.286834] input: ELAN0672:00 04F3:3187 Touchpad as /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-0/i2c-ELAN0672:00/0018:04F3:3187.0002/input/input9
> [    2.286873] hid-generic 0018:04F3:3187.0002: input,hidraw1: I2C HID v1.00 Mouse [ELAN0672:00 04F3:3187] on i2c-ELAN0672:00
> ...
> [    2.337123] input: ELAN0672:00 04F3:3187 Mouse as /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-0/i2c-ELAN0672:00/0018:04F3:3187.0002/input/input10
> [    2.337173] input: ELAN0672:00 04F3:3187 Touchpad as /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-0/i2c-ELAN0672:00/0018:04F3:3187.0002/input/input12
> [    2.337212] hid-multitouch 0018:04F3:3187.0002: input,hidraw1: I2C HID v1.00 Mouse [ELAN0672:00 04F3:3187] on i2c-ELAN0672:00
> 
> 
> So the touchpad seems to have the PS/2 fallback, and then switches to
> i2c-HID. However, with PixArt the PS/2 touchpad isn't initialized, and
> doesn't answered to i2c-hid (or is too much initialized, not sure).

I see. It is interesting that the first probe fails:

[    1.649119] psmouse serio1: pixart_ps2: init: Unable to query PixArt touchpad hardware.


but then it goes and detects it a bit later:

[    1.945075] input: PS/2 PixArt clickpad as /devices/platform/i8042/serio1/input/input5

It would be curious to get the logs of the failing case with
i8042.debug=1

Anyway, I reverted the patch adding the driver and will send a pull
request to Linus soon.

Thanks.

-- 
Dmitry