[lkml]   [2016]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] usb: dwc3: gadget: Avoid race between dwc3 interrupt handler and irq thread handler
2016-12-27 12:05 GMT+01:00 Felipe Balbi <>:
> Hi,
> Lu Baolu <> 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.
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?


> --
> balbi

Janusz Dziedzic

 \ /
  Last update: 2016-12-28 16:28    [W:0.114 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site