On Wed, Aug 27, 2008 at 09:03:08AM -0300, Cesar Eduardo Barros wrote: > Andy Green escreveu: >> No, one doesn't expect the hardware USB unit to go insane until the >> device is reset because we were a little delayed servicing its >> interrupt! I guess the same can happen in Linux if there was ever long >> service time ISR with higher priority that pushed out this one's latency. > > Wait... THAT would explain why the USB gets stuck on cpufreq if it is in > use during a frequency transition, but only if it is in use. The cpufreq > frequency switch pauses the clock for the whole device for many clocks, > while waiting for the PLL to recover. That's more than enough to cause a > very high interrupt latency.
maybe, but the routines in question are only used during control point transfers, specifically device enumeration. Endpoint 0 works completely different from the actual bulk/irq endpoints used during transfers. -- - Harald Welte <[EMAIL PROTECTED]> http://openmoko.org/ ============================================================================ Software for the world's first truly open Free Software mobile phone
