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

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

On Tue, Jan 27, 2026 at 05:11:48AM -0500, correctmost wrote:
> On Tue, Jan 27, 2026, at 3:42 AM, Mika Westerberg wrote:
> > On Tue, Jan 27, 2026 at 01:52:01AM -0500, correctmost wrote:
> >> On Mon, Jan 26, 2026, at 8:53 AM, Mika Westerberg wrote:
> >> > On Sat, Jan 24, 2026 at 10:38:14PM -0500, correctmost wrote:
> >> >> I am seeing mixed results with those i2c config changes, depending on which modules are included in the initramfs image.
> >> >> 
> >> >> Build info for both tests:
> >> >> - Commit c072629f05d7
> >> >> - CONFIG_I2C_DESIGNWARE_CORE=m
> >> >> - CONFIG_I2C_DESIGNWARE_PLATFORM=m
> >> >> 
> >> >> --> Test 1 - Various i2c modules absent from initramfs
> >> >> 
> >> >> Modules:
> >> >> - drivers/dma/idma64.ko.zst present in initramfs
> >> >> - drivers/hid/i2c-hid/{i2c-hid-acpi.ko.zst,i2c-hid.ko.zst} absent from initramfs
> >> >> - drivers/i2c/busses/{i2c-designware-core.ko.zst,i2c-designware-platform.ko.zst,i2c-i801.ko.zst} absent from initramfs
> >> >> - drivers/i2c/{i2c-mux.ko.zst,i2c-smbus.ko.zst} absent from initramfs
> >> >> 
> >> >> Result: The touchpad works, but there are still IRQ #27 messages:
> >> >
> >> > And the touchpad is working fine after boot too?
> >> 
> >> Yep, the touchpad seems to work fine in my desktop environment after booting and logging in.
> >
> > Can you do one more experiment?
> >
> > Add "modprobe.blacklist=idma64" in the command line too (keep everything
> > else as they are now). Does the touchpad still work and do you still get
> > the warning? Please share full dmesg.
> 
> Test 1 - modprobe.blacklist=idma64
> 
> The IRQ warning is present and the touchpad still works, but I think that's because the idma64 module is still loaded (the full log is attached):
> 
> intel-lpss 0000:00:15.0: enabling device (0004 -> 0006)
> idma64 idma64.0: Found Intel integrated DMA 64-bit
> intel-lpss 0000:00:15.3: enabling device (0004 -> 0006)
> idma64 idma64.1: Found Intel integrated DMA 64-bit

Okay can you set CONFIG_INTEL_IDMA64=n in .config? That should prevent it
from loading. Keep the rest as it was.