Hi Tom, On Tue Nov 18, 2025 at 3:08 PM CET, Tom Rini wrote: > On Tue, Nov 18, 2025 at 11:40:28AM +0100, Markus Schneider-Pargmann (TI.com) > wrote: > >> Currently once a driver matched the compatible string of a device, other >> drivers are ignored. If the first matching driver returns -ENODEV, no >> other possibly matching drivers are iterated with that compatible of the >> device. Instead the next compatible in the list of compatibles is >> selected, assuming only one driver matches one compatible at a time. >> >> To be able to use the bind function to return -ENODEV and continue >> matching other drivers with the same compatible, move the for loop a bit >> to continue the for loop after -ENODEV was returned. >> >> This is required for ti-musb-host and ti-musb-peripheral which both >> match on the same device but differ based on the dr_mode DT property. >> Depending on this property, the driver is either UCLASS_USB or >> UCLASS_USB_GADGET_GENERIc. By checking the DT property in the bind >> function and returning -ENODEV the other driver can probe instead. >> >> Signed-off-by: Markus Schneider-Pargmann (TI.com) <[email protected]> >> --- >> drivers/core/lists.c | 62 >> +++++++++++++++++++++++++++------------------------- >> 1 file changed, 32 insertions(+), 30 deletions(-) > > This seems like a big generic change (with potential performance > impact?) for a rather specific case. I assume the linux kernel simply > doesn't have this issue by handling OTG differently. So is there some > other way we can handle this here?
I didn't find a nice way to do this differently. I did have a different idea to do this by overriding the compatible of the parent node of the usb devices. But I didn't like that idea so I proposed this solution. But I would be happy to hear about other ideas. For the performance part: I don't think this reduces performance in most cases. This will only add overhead through additional iterations if a driver with a matching compatible has a bind function that returns -ENODEV. In all other cases this should not add any iterations to the loops. Grepping through the code a bit, I don't think returning -ENODEV in bind() is widely used at the moment. Best Markus
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