Mutexes in USB callbacks ?
M. Warner Losh
imp at bsdimp.com
Sat Sep 3 07:21:41 PDT 2005
In message: <20050903.081802.78021370.imp at bsdimp.com>
M. Warner Losh <imp at bsdimp.com> writes:
: In message: <200509031614.51362.sebastien.bourdeauducq at gmail.com>
: Sebastien <sebastien.bourdeauducq at gmail.com> writes:
: : Hello,
: : Is it finally possible or not to acquire a mutex in an USB callback function,
: : under FreeBSD 5-STABLE ?
: : I have controversial information about this :(
:
: Since the callback functions are called from an interrupt handler
: which is an ithread protected by Giant, there should be no problems
: doing this.
However, since it is an ithread, and usb is a commonly shared device,
any sleeping you do there will delay other device's interrupt hanlders
from running.
Warner
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