On 05/23/2014 03:32 PM, George Cherian wrote: > On 5/23/2014 3:00 PM, Daniel Mack wrote: >> On AM33xx platforms, unplugging a device in the middle of an active >> transfer leads to a drop of MUSB_DEVCTL_HM in MUSB_DEVCTL before the >> system is informed about a disconnect. This consequently makes the musb >> core call the gadget code to handle the interrupt request, which then >> crashes the kernel because the relevant pointers haven't been set up >> for gadget mode. >> >> To fix this, use is_host_active() rather than (devctl & MUSB_DEVCTL_HM) >> in musb_interrupt() and musb_dma_completion() to detect whether the >> controller is in host or peripheral mode. This information is provided >> by the driver logic and does not rely on register contents. > > Yes w.r.t AM33xx platform this looks okay. But since its a core file > used by different > implementations am not sure of any possible issues. I thought about that, too. But then again, musb->is_host should never change its state while there are active users, and it generally seems like a more reliably source of information than the register set. In any way, it fixes a NULL pointer Ooops when hot-plugging devices. Thanks, Daniel -- 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
