lkml.org 
[lkml]   [2023]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v3 0/5] Add function suspend/resume and remote wakeup support
From


On 2/6/2023 5:24 PM, Thinh Nguyen wrote:
> Hi Elson,
>
> On Mon, Feb 06, 2023, Elson Roy Serrao wrote:
>> Changes in v3
>> - Modified rw_capable flag to reflect the gadgets capability for wakeup
>> signalling.
>> - Added a check to configure wakeup bit in bmAttributes only if gadget
>> is capable of triggering wakeup.
>> - Implemented a gadget op for composite layer to inform UDC whether device
>> is configured for remote wakeup.
>> - Added a check in __usb_gadget_wakeup() API to trigger wakeup only if the
>> device is configured for it.
>> - Cosmetic changes in dwc3_gadget_func_wakeup() API.
>>
>> Changes in v2
>> - Added a flag to indicate whether the device is remote wakeup capable.
>> - Added an async parameter to _dwc3_gadget_wakeup() API and few cosmetic
>> changes.
>> - Added flags to reflect the state of function suspend and function remote
>> wakeup to usb_function struct rather than function specific struct (f_ecm).
>> - Changed the dwc3_gadget_func__wakeup() API to run synchronously by first
>> checking the link state and then sending the device notification. Also
>> added debug log for DEVICE_NOTIFICATION generic cmd.
>> - Added changes to arm the device for remotewakeup/function remotewakeup
>> only if device is capable.
>>
>> An usb device can initate a remote wakeup and bring the link out of
>> suspend as dictated by the DEVICE_REMOTE_WAKEUP feature selector.
>> To achieve this an interface can invoke gadget_wakeup op and wait for the
>> device to come out of LPM. But the current polling based implementation
>> fails if the host takes a long time to drive the resume signaling specially
>> in high speed capable devices. Switching to an interrupt based approach is
>> more robust and efficient. This can be leveraged by enabling link status
>> change events and triggering a gadget resume when the link comes to active
>> state.
>>
>> If the device is enhanced super-speed capable, individual interfaces can
>> also be put into suspend state. An interface can be in function suspend
>> state even when the device is not in suspend state. Function suspend state
>> is retained throughout the device suspend entry and exit process.
>> A function can be put to function suspend through FUNCTION_SUSPEND feature
>> selector sent by the host. This setup packet also decides whether that
>> function is capable of initiating a function remote wakeup. When the
>> function sends a wakeup notification to the host the link must be first
>> brought to a non-U0 state and then this notification is sent.
>>
>> This change adds the infrastructure needed to support the above
>> functionalities.
>>
>> Elson Roy Serrao (5):
>> usb: gadget: Properly configure the device for remote wakeup
>> usb: dwc3: Add remote wakeup handling
>> usb: gadget: Add function wakeup support
>> usb: dwc3: Add function suspend and function wakeup support
>> usb: gadget: f_ecm: Add suspend/resume and remote wakeup support
>>
>> drivers/usb/dwc3/core.h | 5 ++
>> drivers/usb/dwc3/debug.h | 2 +
>> drivers/usb/dwc3/ep0.c | 16 ++---
>> drivers/usb/dwc3/gadget.c | 110 +++++++++++++++++++++++++++++++---
>> drivers/usb/gadget/composite.c | 50 +++++++++++++++-
>> drivers/usb/gadget/function/f_ecm.c | 68 +++++++++++++++++++++
>> drivers/usb/gadget/function/u_ether.c | 63 +++++++++++++++++++
>> drivers/usb/gadget/function/u_ether.h | 4 ++
>> drivers/usb/gadget/udc/core.c | 46 ++++++++++++++
>> drivers/usb/gadget/udc/trace.h | 5 ++
>> include/linux/usb/composite.h | 6 ++
>> include/linux/usb/gadget.h | 12 ++++
>> 12 files changed, 371 insertions(+), 16 deletions(-)
>>
>> --
>> 2.7.4
>>
>
> Hi Elson,
>
> Thanks for your patches! I provided some comments. Hopefully they can be
> merged soon.
>
> Thanks,
> Thinh

Hi Thinh

Thank you for your feedback/comments. I will address them in v4.

Regards
Elson

\
 
 \ /
  Last update: 2023-03-27 00:11    [W:0.173 / U:1.984 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site