umcs (4-Port-USB-serial) triggering way too much ehci IRQs

Lev Serebryakov lev at
Tue Sep 17 19:03:42 UTC 2013

Hello, Hans.
You wrote 17 сентября 2013 г., 13:24:26:

HPS> Try this patch and see what happens:
 It could throttle interrupts, but it doesn't explain, why device spams with
interrupts when all ports are closed and all UART interrupts are disabled!

HPS> BTW: I see that the umcs driver shouldn't do synchronous control 
HPS> transfers from the USB interrupt transfer callback. This should be 
HPS> postponed into some worker thread, for example the USB explore thread. 
HPS> See USB audio driver for an example.
 I've copied code from some other ucom driver... I'll take a look at USB

// Black Lion AKA Lev Serebryakov <lev at>

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