€•94      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ/translations/zh_CN/usb/dwc3”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ/translations/zh_TW/usb/dwc3”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ/translations/it_IT/usb/dwc3”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ/translations/ja_JP/usb/dwc3”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ/translations/ko_KR/usb/dwc3”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ/translations/sp_SP/usb/dwc3”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒDWC3 driver”h]”hŒDWC3 driver”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒ6/var/lib/git/docbuild/linux/Documentation/usb/dwc3.rst”h Kubh¢)”}”(hhh]”(h§)”}”(hŒTODO”h]”hŒTODO”…””}”(hhºhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh·hžhhŸh¶h KubhŒ	paragraph”“”)”}”(hŒ&Please pick something while reading :)”h]”hŒ&Please pick something while reading :)”…””}”(hhÊhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K	hh·hžhubhŒbullet_list”“”)”}”(hhh]”hŒ	list_item”“”)”}”(hXÀ  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).”h]”(hÉ)”}”(hŒ.Convert interrupt handler to per-ep-thread-irq”h]”hŒ.Convert interrupt handler to per-ep-thread-irq”…””}”(hhãhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KhhßubhÉ)”}”(hŒpAs it turns out some DWC3-commands ~1ms to complete. Currently we spin
until the command completes which is bad.”h]”hŒpAs it turns out some DWC3-commands ~1ms to complete. Currently we spin
until the command completes which is bad.”…””}”(hhñhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KhhßubhÉ)”}”(hŒImplementation idea:”h]”hŒImplementation idea:”…””}”(hhÿhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KhhßubhÙ)”}”(hhh]”(hÞ)”}”(hŒþdwc core implements a demultiplexing irq chip for interrupts per
endpoint. The interrupt numbers are allocated during probe and belong
to the device. If MSI provides per-endpoint interrupt this dummy
interrupt chip can be replaced with "real" interrupts.”h]”hÉ)”}”(hŒþdwc core implements a demultiplexing irq chip for interrupts per
endpoint. The interrupt numbers are allocated during probe and belong
to the device. If MSI provides per-endpoint interrupt this dummy
interrupt chip can be replaced with "real" interrupts.”h]”hX  dwc core implements a demultiplexing irq chip for interrupts per
endpoint. The interrupt numbers are allocated during probe and belong
to the device. If MSI provides per-endpoint interrupt this dummy
interrupt chip can be replaced with â€œrealâ€ interrupts.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝhj  ubhÞ)”}”(hŒ˜interrupts are requested / allocated on usb_ep_enable() and removed on
usb_ep_disable(). Worst case are 32 interrupts, the lower limit is two
for ep0/1.”h]”hÉ)”}”(hŒ˜interrupts are requested / allocated on usb_ep_enable() and removed on
usb_ep_disable(). Worst case are 32 interrupts, the lower limit is two
for ep0/1.”h]”hŒ˜interrupts are requested / allocated on usb_ep_enable() and removed on
usb_ep_disable(). Worst case are 32 interrupts, the lower limit is two
for ep0/1.”…””}”(hj,  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khj(  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝhj  ubhÞ)”}”(hŒbdwc3_send_gadget_ep_cmd() will sleep in wait_for_completion_timeout()
until the command completes.”h]”hÉ)”}”(hŒbdwc3_send_gadget_ep_cmd() will sleep in wait_for_completion_timeout()
until the command completes.”h]”hŒbdwc3_send_gadget_ep_cmd() will sleep in wait_for_completion_timeout()
until the command completes.”…””}”(hjD  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khj@  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝhj  ubhÞ)”}”(hX  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.
”h]”(hÉ)”}”(hŒ9the interrupt handler is split into the following pieces:”h]”hŒ9the interrupt handler is split into the following pieces:”…””}”(hj\  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h KhjX  ubhÙ)”}”(hhh]”(hÞ)”}”(hŒÏprimary handler of the device
goes through every event and calls generic_handle_irq() for event
it. On return from generic_handle_irq() in acknowledges the event
counter so interrupt goes away (eventually).
”h]”hÉ)”}”(hŒÎprimary handler of the device
goes through every event and calls generic_handle_irq() for event
it. On return from generic_handle_irq() in acknowledges the event
counter so interrupt goes away (eventually).”h]”hŒÎprimary handler of the device
goes through every event and calls generic_handle_irq() for event
it. On return from generic_handle_irq() in acknowledges the event
counter so interrupt goes away (eventually).”…””}”(hjq  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khjm  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝhjj  ubhÞ)”}”(hŒ$threaded handler of the device
none
”h]”hÉ)”}”(hŒ#threaded handler of the device
none”h]”hŒ#threaded handler of the device
none”…””}”(hj‰  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K"hj…  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝhjj  ubhÞ)”}”(hXN  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.
”h]”hÉ)”}”(hXM  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.”h]”hXO  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 donâ€™t process event X prio Y
where X > Y.”…””}”(hj¡  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K%hj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝhjj  ubhÞ)”}”(hŒ}threaded handler of the EP-interrupt
handles the remaining EP work which might sleep such as waiting
for command completion.
”h]”hÉ)”}”(hŒ|threaded handler of the EP-interrupt
handles the remaining EP work which might sleep such as waiting
for command completion.”h]”hŒ|threaded handler of the EP-interrupt
handles the remaining EP work which might sleep such as waiting
for command completion.”…””}”(hj¹  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K-hjµ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝhjj  ubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ-”uh1hØhŸh¶h KhjX  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝhj  ubeh}”(h]”h ]”h"]”h$]”h&]”jÓ  jÔ  uh1hØhŸh¶h KhhßubhÉ)”}”(hŒLatency:”h]”hŒLatency:”…””}”(hjá  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K1hhßubhŒblock_quote”“”)”}”(hŒ¯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).”h]”hÉ)”}”(hŒ¯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).”h]”hŒ¯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).”…””}”(hjõ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h K3hjñ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jï  hŸh¶h K3hhßubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝhhÚhžhhŸh¶h Nubah}”(h]”h ]”h"]”h$]”h&]”jÓ  jÔ  uh1hØhŸh¶h Khh·hžhubeh}”(h]”Œtodo”ah ]”h"]”Œtodo”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kubeh}”(h]”Œdwc3-driver”ah ]”h"]”Œdwc3 driver”ah$]”h&]”uh1h¡hhhžhhŸh¶h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h¶uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¦NŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jH  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h¶Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(j"  j  j  j  uŒ	nametypes”}”(j"  ‰j  ‰uh}”(j  h£j  h·uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
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