Hi David, I know this is a pretty old thread. I tried searching for the LKML etiquette on something like this and came up empty. If I should start a new thread, let me know.
After what I learned from the last thread, I dropped the idea of using the device controller from the Dell tablet I had. A few months later, I learned that some overseas electronics companies are now making dual-boot tablets, that support both Android and generic x86 operating systems through an IA32 UEFI firmware. I did some research on the devices, and found that they support interaction over USB with the Android tools ADB and fastboot, which indicated to me that they likely had a working USB device controller. With my curiosity piqued, I acquired one. My testing confirmed that the installed Android OS had the capability of utilizing both the host and device controllers, and allowed file transfer over MTP, as well as USB networking. After discovering that much of the kernel code supporting Baytrail had yet to be mainlined, I shelved the device for a few months. In the last few days, I've revisited the tablet, and replaced the second OS that came on it with a Linux distribution running the mainline kernel, compiled with DWC3 and OTG support. After booting the tablet and attempting to load a gadget module, I had a bout of deja vu. The device controller doesn't appear in the list of PCI devices. When attempting to load a gadget module, the kernel log reports: > udc-core: couldn't find an available UDC After reviewing this thread, I confirmed that the device id 8086:0f37 does not appear in the output of 'lspci -nn', but 8086:0f35 does. The dual-boot capability of the device seems to be implemented by switching between two distinct firmwares, but I can't be sure. If that is the case, I'm wondering if the PC compatible firmware just doesn't expose the device controller for some reason. Alternatively, like Felipe mentioned, I wonder if there's not a muxer between the phy and device/host controllers that needs to be configured somehow. Do you have any light to shed on this? Best, Joseph -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
