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

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

On Mon, Feb 02, 2026 at 03:38:21AM -0500, correctmost wrote:
> >
> > static irqreturn_t idma64_irq(int irq, void *dev)
> > {
> > 	struct idma64 *idma64 = dev;
> > 	u32 status = dma_readl(idma64, STATUS_INT);
> > 	u32 status_xfer;
> > 	u32 status_err;
> > 	unsigned short i;
> >
> > #if 0
> > 	/* Since IRQ may be shared, check if DMA controller is powered on */
> > 	if (status == GENMASK(31, 0))
> > 		return IRQ_NONE;
> > #endif
> >
> > 	dev_vdbg(idma64->dma.dev, "%s: status=%#x\n", __func__, status);
> >
> >
> > I would like to see what's the difference in "working" wrt. I2C-HD messages
> > above. If you can provide full dmesg again? Thanks!
> 
> In the previous test, I had commented out pm_runtime_* calls in intel-lpss-pci.c.  I restored those lines and then applied the if 0 patch above (full log attached).

Thanks!

The I2C DW behaviour differs between the cases. When it fails it holds the
SCL line but then the timeout triggers.

Could you drop the above hack again so that it should "fail". Then build
the kernel with CONFIG_PREEMPT_VOLUNTARY=y and add the below hack. Perhaps
this is just lucky timing? Please try a couple of boots and make sure the
results are the same each time.

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 45bfca05bb30..1e2150390809 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -1053,6 +1053,7 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev)
 		scnprintf(adap->name, sizeof(adap->name),
 			  "Synopsys DesignWare I2C adapter");
 	adap->retries = 3;
+	adap->timeout = msecs_to_jiffies(5000);
 	adap->algo = &i2c_dw_algo;
 	adap->quirks = &i2c_dw_quirks;
 	adap->dev.parent = dev->dev;