On Tue, 2014-06-17 at 09:31 +0200, Vlad Ungureanu wrote: > Hello, > > I recently started to develop a USB kernel driver for a GoogleSummer Of Code > project and I'm running in some small issues. The source code is available at > https://github.com/ungureanuvladvictor/ADK-Driver/blob/master/adk-driver.c . The debugging printks in your open method (around line 104) are obviously wrong. You test for NULL but then use the NULL pointer for debugging. The same bug in adk_release(). adk_delete() has a memory leak. You don't free the buffer. In adk_probe() please use the testing macros for endpoint type and direction. > The driver matches the VID/PID of a LG Nexus5 and tries in the probe function > to switch it to ADK Mode *Accessory Development Kit Mode*. Afterwards the same > driver should deal with the device in ADK Mode and should find it's bulk IN/OUT > EPs. > > The problem is that my probe callback is called twice for each mode of the > device, normal mode and ADK mode. It is called for each interface. > If you look at this Gist: > https://gist.github.com/ungureanuvladvictor/44bc345037916bbd0bf1 lines 19 and > 25 is where the probe function is called for the normal device. Lines 58 and 66 > are for the device in ADK mode. As I read from the documentation the probe > callback is called when a device that matches my device_table is found by the > usb core. In the log I see that the usb core calls probe for each interface it > has: lines 16, 22 and 55, 63. USB drivers are drivers for interfaces, not whole devices. Each interface of a device is probed separately in turn. If you have a device that exposes two mutually exclusive access methods in the same configuration, you need to claim the second interface for the undesired method in the probe method and refuse to bind to the undesired interface in the probe method, as you cannot reliably predict which interface is probed first. Look at cdc-acm for an example of claiming other interfaces from within probe() HTH Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
