2016-12-27 12:05 GMT+01:00 Felipe Balbi <balbi@xxxxxxxxxx>: > Hi, > > Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> writes: >> On 12/26/2016 04:01 PM, Baolin Wang wrote: >>> On some platfroms(like x86 platform), when one core is running the USB gadget >>> irq thread handler by dwc3_thread_interrupt(), meanwhile another core also can >>> respond other interrupts from dwc3 controller and modify the event buffer by >>> dwc3_interrupt() function, that will cause getting the wrong event count in >>> irq thread handler to make the USB function abnormal. >>> >>> We should add spin_lock/unlock() in dwc3_check_event_buf() to avoid this race. >> >> Why not spin_lock_irq ones? This lock seems to be used in both >> normal and interrupt threads. Or, I missed anything? > > this is top half handler. Interrupts are already disabled. > BTW, We don't use spin_lock in top half handler. Maybe we should/can switch all spin_lock_irqsave() to simple spin_lock() in the thread/callbacks? Or there is a reason to use irqsave() version? BR Janusz > -- > balbi -- Janusz Dziedzic -- 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
