On Tue, Oct 08, 2024 at 04:09:45PM -0400, Frank Li wrote: > On Tue, Aug 13, 2024 at 02:07:01PM -0400, Frank Li wrote: > > On Sun, Aug 11, 2024 at 08:11:57PM -0700, Bjorn Andersson wrote: > > > The USB IP-block found in most Qualcomm platforms is modelled in the > > > Linux kernel as 3 different independent device drivers, but as shown by > > > the already existing layering violations in the Qualcomm glue driver > > > they can not be operated independently. > > > > > > With the current implementation, the glue driver registers the core and > > > has no way to know when this is done. As a result, e.g. the suspend > > > callbacks needs to guard against NULL pointer dereferences when trying > > > to peek into the struct dwc3 found in the drvdata of the child. > > > > > > Missing from the upstream Qualcomm USB support is handling of role > > > switching, in which the glue needs to be notified upon DRD mode changes. > > > Several attempts has been made through the years to register callbacks > > > etc, but they always fall short when it comes to handling of the core's > > > probe deferral on resources etc. > > > > > > Furhtermore, the DeviceTree binding is a direct representation of the > > > Linux driver model, and doesn't necessarily describe "the USB IP-block". > > > > > > This series therefor attempts to flatten the driver split, and operate > > > the glue and core out of the same platform_device instance. And in order > > > to do this, the DeviceTree representation of the IP block is flattened. > > > > Bjorn Andersson: > Any follow up on this thread? > Thanks for reaching out, Frank. I did pick this up again a few days back. I'm struggling with Rob's request for not peeking into struct property and/or utilizing overlays. Hoping to figure this out shortly, so I can get v3 in shape. Regards, Bjorn
