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

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

On Wed, Feb 04, 2026 at 10:12:57AM -0500, correctmost wrote:
> > I will try to debug the config issue and retest the touchpad with the 
> > proper config changes.
> 
> After fixing the config issue, I now see "Dynamic Preempt: voluntary" in
> the dmesg output.  I also see "# CONFIG_HID_BPF is not set" in
> /proc/config.gz.
> 
> The "probe with driver hid-generic failed with error -22" message is
> still present and the touchpad doesn't work (full log attached).

Thanks!

I don't see any other way than adding even more debug. It really should at
least be able to parse the report descriptor as that's exactly the same as
in working case but let's try to figure why it fails. Can you add again on
top of everything this one:

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index a5b3a8ca2fcb..0a6e373bf899 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1282,6 +1282,8 @@ int hid_open_report(struct hid_device *device)
 		return -ENODEV;
 	size = device->bpf_rsize;
 
+	hid_info(device, "open_report, start %p, size %d\n", start, size);
+
 	if (device->driver->report_fixup) {
 		/*
 		 * device->driver->report_fixup() needs to work
@@ -1304,6 +1306,8 @@ int hid_open_report(struct hid_device *device)
 		kfree(buf);
 		if (start == NULL)
 			return -ENOMEM;
+
+		hid_info(device, "open_report fixup, start %p, size %d\n", start, size);
 	}
 
 	device->rdesc = start;
@@ -1333,6 +1337,8 @@ int hid_open_report(struct hid_device *device)
 	while ((next = fetch_item(start, end, &item)) != NULL) {
 		start = next;
 
+		hid_info(device, "parsing, start %p", start);
+
 		if (item.format != HID_ITEM_FORMAT_SHORT) {
 			hid_err(device, "unexpected long global item\n");
 			goto err;
@@ -2736,6 +2742,8 @@ static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
 	const struct hid_device_id *id;
 	int ret;
 
+	hid_info(hdev, "probe starts\n");
+
 	if (!hdev->bpf_rsize) {
 		/* we keep a reference to the currently scanned report descriptor */
 		const __u8  *original_rdesc = hdev->bpf_rdesc;
@@ -2753,6 +2761,8 @@ static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
 		hdev->bpf_rdesc = call_hid_bpf_rdesc_fixup(hdev, hdev->dev_rdesc,
 							   &hdev->bpf_rsize);
 
+		hid_info(hdev, "new rdesc %p size %d", hdev->bpf_rdesc, hdev->bpf_rsize);
+
 		/* the report descriptor changed, we need to re-scan it */
 		if (original_rdesc != hdev->bpf_rdesc) {
 			hdev->group = 0;
diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c
index c2de916747de..63ea9c0c6ce1 100644
--- a/drivers/hid/hid-generic.c
+++ b/drivers/hid/hid-generic.c
@@ -63,6 +63,8 @@ static int hid_generic_probe(struct hid_device *hdev,
 
 	hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
 
+	hid_info(hdev, "generic probe\n");
+
 	ret = hid_parse(hdev);
 	if (ret)
 		return ret;
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 5a183af3d5c6..99a12ef970bd 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -800,6 +800,8 @@ static int i2c_hid_parse(struct hid_device *hid)
 	if (ret)
 		dbg_hid("parsing report descriptor failed\n");
 
+	i2c_hid_dbg(ihid, "Report Descriptor %p, size %d\n", rdesc, rsize);
+
 out:
 	if (!use_override)
 		kfree(rdesc);