Hi Paul On 23/07/2021 08:49, Paul Kocialkowski wrote: > Hi Daniel, > > On Thu 22 Jul 21, 21:33, Daniel Scally wrote: >> The ov8865 driver is one of those that can be connected to a CIO2 >> device by the cio2-bridge code. This means that the absence of an >> endpoint for this device is not necessarily fatal, as one might be >> built by the cio2-bridge when it probes. Return -EPROBE_DEFER if no >> endpoint is found rather than a fatal error. > Is this an error that you have actually seen in practice? Yes > My understanding is that this function should return the handle to the *local* > fwnode graph endpoint, which relates to the static device-tree description > and should be unrelated to another driver probing. > > So as far as I can see, this should not be needed (but correct me if I'm wrong). It's a newly possible scenario - some laptops with Intel IPU3s have ACPI that is _creative_,. and rather than define the endpoints in an ACPI device's _DSD they're encoded within a buffer that's against the sensor devices instead. We're parsing those out and building the fwnode graph using software nodes in the ipu3-cio2 driver: https://elixir.bootlin.com/linux/v5.14-rc2/source/drivers/media/pci/intel/ipu3/cio2-bridge.c#L166 But that means there's no endpoint for the sensor until ipu3-cio2 has probed. Thanks Dan > > Cheers, > > Paul > >> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx> >> --- >> drivers/media/i2c/ov8865.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/media/i2c/ov8865.c b/drivers/media/i2c/ov8865.c >> index 2ef146e7e7ef..66182142c28b 100644 >> --- a/drivers/media/i2c/ov8865.c >> +++ b/drivers/media/i2c/ov8865.c >> @@ -2796,10 +2796,8 @@ static int ov8865_probe(struct i2c_client *client) >> /* Graph Endpoint */ >> >> handle = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL); >> - if (!handle) { >> - dev_err(dev, "unable to find endpoint node\n"); >> - return -EINVAL; >> - } >> + if (!handle) >> + return -EPROBE_DEFER; >> >> sensor->endpoint.bus_type = V4L2_MBUS_CSI2_DPHY; >> >> -- >> 2.25.1 >>
