Hi Sakari, On Wed, Jun 12, 2024 at 2:47 PM Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote: > > Hi Rafael, > > On Wed, Jun 12, 2024 at 02:32:26PM +0200, Rafael J. Wysocki wrote: > > > > > > I just hit the same problem on another Dell laptop. It seems that > > > > > > all Dell laptops with IPU6 camera from the Tiger Lake, Alder Lake > > > > > > and Raptor Lake generations suffer from this problem. > > > > > > > > > > > > So instead of playing whack a mole with DMI matches we should > > > > > > simply disable ACPI MIPI DISCO support on all Dell laptops > > > > > > with those CPUs. I'm preparing a fix for this to replace > > > > > > the DMI matching now. > > > > > > > > > > DisCo for Imaging support shouldn't be dropped on these systems, and this > > > > > isn't what your patch does either. Instead the ACPI graph port nodes (as > > > > > per Linux specific definitions) are simply dropped, i.e. this isn't related > > > > > to DisCo for Imaging at all. > > > > > > > > So it looks like the changelog of that patch could be improved, right? > > > > > > Well, yes. The reason the function is in the file is that nearly all camera > > > related parsing is located there, not that it would be related to DisCo for > > > Imaging as such. > > > > So IIUC the camera graph port nodes are created by default with the > > help of the firmware-supplied information, but if that is defective a > > quirk can be added to skip the creation of those ports in which case > > they will be created elsewhere. > > > > Is this correct? > > Yes. So it would be good to add a comment to this effect to acpi_nondev_subnode_extract() where acpi_graph_ignore_port() is called. And there is a somewhat tangential question that occurred to me: If the nodes are created elsewhere when acpi_graph_ignore_port() is true, why is it necessary to consult the platform firmware for the information on them at all? Wouldn't it be better to simply always create them elsewhere?
