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Diffstat (limited to 'Documentation/usb/dwc3.txt')
-rw-r--r-- | Documentation/usb/dwc3.txt | 45 |
1 files changed, 0 insertions, 45 deletions
diff --git a/Documentation/usb/dwc3.txt b/Documentation/usb/dwc3.txt deleted file mode 100644 index 1d02c01d1c7..00000000000 --- a/Documentation/usb/dwc3.txt +++ /dev/null @@ -1,45 +0,0 @@ - - TODO -~~~~~~ -Please pick something while reading :) - -- Convert interrupt handler to per-ep-thread-irq - - As it turns out some DWC3-commands ~1ms to complete. Currently we spin - until the command completes which is bad. - - Implementation idea: - - dwc core implements a demultiplexing irq chip for interrupts per - endpoint. The interrupt numbers are allocated during probe and belong - to the device. If MSI provides per-endpoint interrupt this dummy - interrupt chip can be replaced with "real" interrupts. - - interrupts are requested / allocated on usb_ep_enable() and removed on - usb_ep_disable(). Worst case are 32 interrupts, the lower limit is two - for ep0/1. - - dwc3_send_gadget_ep_cmd() will sleep in wait_for_completion_timeout() - until the command completes. - - the interrupt handler is split into the following pieces: - - primary handler of the device - goes through every event and calls generic_handle_irq() for event - it. On return from generic_handle_irq() in acknowledges the event - counter so interrupt goes away (eventually). - - - threaded handler of the device - none - - - primary handler of the EP-interrupt - reads the event and tries to process it. Everything that requires - sleeping is handed over to the Thread. The event is saved in an - per-endpoint data-structure. - We probably have to pay attention not to process events once we - handed something to thread so we don't process event X prio Y - where X > Y. - - - threaded handler of the EP-interrupt - handles the remaining EP work which might sleep such as waiting - for command completion. - - Latency: - There should be no increase in latency since the interrupt-thread has a - high priority and will be run before an average task in user land - (except the user changed priorities). |