On Mon, Apr 24, 2017 at 01:25:21PM +0000, Bernhard Walle wrote: > Hi, > > > Peter Chen <peter.chen@xxxxxxx> hat am 24. April 2017 um 05:51 geschrieben: > > > > > The current code logic is: > > - When the resume is received from host, the ci->dirver->resume is > > called, and suspended is cleared. > > - When the reset is received from host, the isr_reset_handler is called, > > and suspended is cleared by _gadget_stop_activity. Since reset is > > called, so ci->driver->resume doesn't need to be called. > > My problem is that dump_stack() doesn't show the complete stackframe. What I see from debug messages is that when I plug a cable (after the host has been suspended) then _gadget_stop_activity is executed before udc_irq. > > My first attempt was to save ci->suspended at the beginning of udc_irq (i.e. before isr_reset_handler is called), but that doesn't work. Even in the beginning of udc_irq ci->suspended is 0. So isr_reset_handler is called before. > > The result is that when I unplug a cable and attach it again, driver->suspended has been called but driver->resume doesn't get called. > > > There is a patch to fix clear suspended even the ci->driver->resume is > > NULL at v4.12-rc1. > > > > usb: chipidea: udc: update gadget state after bus resume > > Thanks for the hint. That makes the second part of my patch irrelevant, but the first part (removing the ci->suspended = 0) is needed in order to make my setup working. > > Any idea to find the cause why reset is called before resume? According to your explanation, that shouldn't be the case? > Since you unplug the cable first, and plug in again. The driver will treat it as connection but not resume event. You may use /sys/class/udc/ci_hdrc.0/state to get udc's connection, eg "not attached" or other states to indicate connection. -- Best Regards, Peter Chen -- 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
