Re: [REGRESSION][BISECTED] Lenovo IdeaPad touchpad does not work when idma64 is present in initramfs

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Thu, Jan 22, 2026 at 05:29:38PM -0500, correctmost wrote:
> On Thu, Jan 22, 2026, at 6:00 AM, Mika Westerberg wrote:
> > On Wed, Jan 21, 2026 at 05:19:17PM +0200, Andy Shevchenko wrote:
> >> > Well I mean if touchpads actually worked prior this idma64 commit and now
> >> > they don't isn't that a regression?
> >> 
> >> I don't think so, because commit did the right thing and just revealed an issue
> >> that was rather hidden. Reverting is not an option.
> >
> > I now looked at both working and non-working /proc/interrupts and when it
> > is working there is no interrupt flood at all:
> >
> >  27:          0          0          0          0       2277          0  
> >         0          0          0          0          0          0 
> > IR-IO-APIC   27-fasteoi   idma64.0, i2c_designware.0
> >
> > This makes me think that perhaps the toucpad is powered off and that causes
> > the issue until I2C HID probes and resets it. I looked at the ACPI tables
> > but I did not (yet) find anything that stands out.
> >
> > I wonder if it was tried to put i2c-designware*.ko and i2c-hid.ko into the
> > initramfs, and does work it around? I would expect so.
> 
> I don't see an i2c-designware module loaded when my touchpad works:
> 
> $ grep -i i2c /proc/modules 
> i2c_i801 40960 0 - Live 0x0000000000000000
> i2c_smbus 20480 1 i2c_i801, Live 0x0000000000000000
> i2c_mux 16384 1 i2c_i801, Live 0x0000000000000000
> i2c_hid_acpi 12288 0 - Live 0x0000000000000000
> i2c_hid 45056 1 i2c_hid_acpi, Live 0x0000000000000000
> i2c_algo_bit 24576 2 xe,i915, Live 0x0000000000000000

Well it must be there. This is from your working log:

[   27.686842] input: ELAN06FA:00 04F3:327E Mouse as /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-13/i2c-ELAN06FA:00/0018:04F3:327E.0001/input/input6
[   27.689119] input: ELAN06FA:00 04F3:327E Touchpad as /devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-13/i2c-ELAN06FA:00/0018:04F3:327E.0001/input/input8
[   27.691257] hid-generic 0018:04F3:327E.0001: input,hidraw0: I2C HID v1.00 Mouse [ELAN06FA:00 04F3:327E] on i2c-ELAN06FA:00

I suspect you have it built-in to the kernel image and that's why it does
not show in the module listing. Can you change that to m:

CONFIG_I2C_DESIGNWARE_CORE=m
CONFIG_I2C_DESIGNWARE_PLATFORM=m

and put to the initramfs? Does that make it work?