On Wed Sep 2 22:15:24 2026 +0100, Sergey Zagursky wrote:
> Since commit c6b1b34b5090 ("media: pci: intel: Add CVS support for IPU
> bridge driver") the internal camera no longer works on laptops where the
> sensor sits behind an IVSC, for example a Dell XPS 16 9640 (IPU6,
> INTC10CF, ov02c10):
>
> intel-ipu6 0000:00:05.0: Found supported sensor OVTI02C1:00
> intel-ipu6 0000:00:05.0: Connected 1 cameras
> ivsc_csi intel_vsc-92335fcf-3203-4472-af93-7b4453ac29da: mei-csi probed
> without device fwnode!
>
> No sensor subdevice is registered, the media graph has no sensor entity
> and userspace finds no camera at all.
>
> ipu_bridge_get_ivsc_csi_dev() first looks for the platform device named
> "intel_vsc" and returns its mei-csi child. That device is created by
> mei_vsc, which on this machine only appears once the LJCA USB bridge and
> its SPI controller have probed, about a second after the IPU6 probe that
> runs the bridge:
>
> 07:59:29.297 platform INTC10CF:00 created (ACPI scan)
> 07:59:41 intel-ipu6 probe -> ipu_bridge_init()
> 07:59:42.391 platform intel_vsc created (mei_vsc)
>
> The commit above added two fallbacks for CVS which match on the ACPI
> companion alone. They are reached for every entry of ivsc_acpi_ids[],
> IVSC IDs included. The IVSC ACPI device has two physical nodes:
>
> INTC10CF:00/physical_node -> platform/INTC10CF:00 (no driver bound)
> INTC10CF:00/physical_node1 -> platform/intel_vsc (mei_vsc)
>
> so bus_find_device_by_acpi_dev(&platform_bus_type, adev) returns the bare
> platform device. ipu_bridge_instantiate_ivsc() then attaches the IVSC
> software node to that device instead of to the mei-csi client, the bridge
> reports success, and the probe is never retried. mei_csi later probes
> without a fwnode, the CSI-2 link is never described, and the sensor ACPI
> device, which has an honoured _DEP on the IVSC device, is never
> enumerated.
>
> Before those fallbacks existed the lookup returned NULL here, the bridge
> failed with -ENODEV and the probe was retried once the IVSC device had
> shown up.
>
> Skip those fallbacks for IVSC devices, keying on the IVSC IDs rather than
> the CVS ones: new CVS IDs keep being added, whereas the IVSC list is
> complete. CVS binds a driver to the ACPI device itself, so matching on the
> companion stays unambiguous there.
>
> Fixes: c6b1b34b5090 ("media: pci: intel: Add CVS support for IPU bridge
> driver")
> Link:
> https://lore.kernel.org/linux-media/[email protected]/
> Cc: [email protected]
> Assisted-by: Claude Code:claude-opus-5
> Signed-off-by: Sergey Zagursky <[email protected]>
> Signed-off-by: Sakari Ailus <[email protected]>
Patch committed.
Thanks,
Sakari Ailus
drivers/media/pci/intel/ipu-bridge.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
---
diff --git a/drivers/media/pci/intel/ipu-bridge.c
b/drivers/media/pci/intel/ipu-bridge.c
index 125fe5da7a60..883a90249602 100644
--- a/drivers/media/pci/intel/ipu-bridge.c
+++ b/drivers/media/pci/intel/ipu-bridge.c
@@ -232,6 +232,19 @@ static const struct acpi_device_id ivsc_acpi_ids[] = {
{ "INTC10FA" }, /* NVL */
};
+/*
+ * The subset of ivsc_acpi_ids[] which are IVSC, rather than CVS, devices. The
+ * CVS IDs are deliberately not listed here: new ones keep being added, whereas
+ * this list is complete.
+ */
+static const struct acpi_device_id ivsc_only_acpi_ids[] = {
+ { "INTC1059" },
+ { "INTC1095" },
+ { "INTC100A" },
+ { "INTC10CF" },
+ { }
+};
+
static struct acpi_device *ipu_bridge_get_ivsc_acpi_dev(struct acpi_device
*adev)
{
unsigned int i;
@@ -283,6 +296,17 @@ static struct device *ipu_bridge_get_ivsc_csi_dev(struct
acpi_device *adev)
return csi_dev;
}
+ /*
+ * The lookups below match on the ACPI companion alone. That is fine for
+ * CVS, which binds a driver to that very device, but not for IVSC:
there
+ * the ACPI device also has a driverless platform device, which would be
+ * returned instead of the mei-csi client. Return NULL for IVSC so that
+ * the caller fails and the probe is retried once the IVSC device shows
+ * up.
+ */
+ if (!acpi_match_device_ids(adev, ivsc_only_acpi_ids))
+ return NULL;
+
/* Try to locate CVS device on the I2C bus */
csi_dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
if (csi_dev)
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