On 11/25/2013 01:50 AM, Xenia Ragiadakou wrote:
[snip]
Also, while you're going through the whole remove-and-add procedure for
endpoints that aren't halted, do you want to hold the bandwidth mutex?
If the procedure isn't atomic, there's a possibility that some other
device could change configs in the middle. This would also prevent
concurrent altsetting changes.
Yes, i need to lock the bandwidth_mutex. I will fix this.
Alan Stern
After i looked at it more carefully, there will be a deadlock if i try
to aqcuire the bandwidth_mutex in reset endpoint code.
In usb_set_configuration(), the bandwidth_mutex is held while
usb_enable_interface() is called for each interface and
usb_enable_interface() will attempt to reset the endpoints via
usb_enable_endpoint() since the 3rd argument is set to true.
So, I think it's not a good idea to try to lock the bandwidth_mutex
given that, right?
ksenia
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