[v2,00/11] usb: dwc3: gadget: Handle streams

Message

Thinh Nguyen May 6, 2020, 2:46 a.m. UTC

Overview of stream transfer requirement:
 * A transfer will have a set of TRBs of the same stream ID.
 * A transfer is started with a stream ID in START_TRANSFER command.
 * A new stream will only start when the previous completes.

Overview of stream events:
 * A "prime" from host indicates that its endpoints are active
   (buffers prepared and ready to receive/transmit data). The controller
   automatically initiates stream if it sees this.
 * A "NoStream" rejection event indicates that the host isn't ready.
   Host will put the endpoint back to idle state. Device may need to
   reinitiate the stream to start transfer again.
 * A Stream Found event means host accepted device initiated stream.
   Nothing needs to be done from driver.

To initiate a stream, the driver will issue START_TRANSFER command with a
stream ID. To reinitiate the stream, the driver must issue END_TRANSFER and
restart the transfer with START_TRANSFER command with the same stream ID.

This implementation handles device-initated streams (e.g. UASP driver).  It
also handles some hosts' quirky behavior where they only prime each endpoint
once.

Prerequisite:
  This series requires DWC_usb32 patch series
  https://patchwork.kernel.org/project/linux-usb/list/?series=269641

  [PATCH 1/2] usb: dwc3: Add support for DWC_usb32 IP
  [PATCH 2/2] usb: dwc3: Get MDWIDTH for DWC_usb32


Changes in v2:
 - Update cover letter
 - Split handling of stream and of transfer completion into smaller patches
 - Reword usb_request->is_last to strictly use for streams
 - Enforce transfer completion handling to only for stream capable endpoints


Thinh Nguyen (11):
  usb: gadget: Introduce usb_request->is_last
  usb: gadget: f_tcm: Inform last stream request
  usb: dwc3: gadget: Continue to process pending requests
  usb: dwc3: gadget: Check for in-progress END_TRANSFER
  usb: dwc3: gadget: Refactor TRB completion handler
  usb: dwc3: gadget: Enable XferComplete event
  usb: dwc3: gadget: Handle XferComplete for streams
  usb: dwc3: gadget: Wait for transfer completion
  usb: dwc3: gadget: Don't prepare beyond a transfer
  usb: dwc3: gadget: Handle stream transfers
  usb: dwc3: gadget: Use SET_EP_PRIME for NoStream

 drivers/usb/dwc3/core.h             |  12 ++
 drivers/usb/dwc3/debug.h            |   2 +
 drivers/usb/dwc3/gadget.c           | 225 +++++++++++++++++++++++++++++++-----
 drivers/usb/gadget/function/f_tcm.c |   3 +
 include/linux/usb/gadget.h          |   3 +
 5 files changed, 215 insertions(+), 30 deletions(-)

Comments

Felipe Balbi May 14, 2020, 10:43 a.m. UTC | #1

Hi,

Thinh Nguyen <[e-mail]> writes:
> Overview of stream transfer requirement:
>  * A transfer will have a set of TRBs of the same stream ID.
>  * A transfer is started with a stream ID in START_TRANSFER command.
>  * A new stream will only start when the previous completes.
>
> Overview of stream events:
>  * A "prime" from host indicates that its endpoints are active
>    (buffers prepared and ready to receive/transmit data). The controller
>    automatically initiates stream if it sees this.
>  * A "NoStream" rejection event indicates that the host isn't ready.
>    Host will put the endpoint back to idle state. Device may need to
>    reinitiate the stream to start transfer again.
>  * A Stream Found event means host accepted device initiated stream.
>    Nothing needs to be done from driver.
>
> To initiate a stream, the driver will issue START_TRANSFER command with a
> stream ID. To reinitiate the stream, the driver must issue END_TRANSFER and
> restart the transfer with START_TRANSFER command with the same stream ID.
>
> This implementation handles device-initated streams (e.g. UASP driver).  It
> also handles some hosts' quirky behavior where they only prime each endpoint
> once.
>
> Prerequisite:
>   This series requires DWC_usb32 patch series
>   https://patchwork.kernel.org/project/linux-usb/list/?series=269641
>
>   [PATCH 1/2] usb: dwc3: Add support for DWC_usb32 IP
>   [PATCH 2/2] usb: dwc3: Get MDWIDTH for DWC_usb32
>
>
> Changes in v2:
>  - Update cover letter
>  - Split handling of stream and of transfer completion into smaller patches
>  - Reword usb_request->is_last to strictly use for streams
>  - Enforce transfer completion handling to only for stream capable endpoints
>
>
> Thinh Nguyen (11):
>   usb: gadget: Introduce usb_request->is_last
>   usb: gadget: f_tcm: Inform last stream request
>   usb: dwc3: gadget: Continue to process pending requests
>   usb: dwc3: gadget: Check for in-progress END_TRANSFER
>   usb: dwc3: gadget: Refactor TRB completion handler
>   usb: dwc3: gadget: Enable XferComplete event
>   usb: dwc3: gadget: Handle XferComplete for streams
>   usb: dwc3: gadget: Wait for transfer completion
>   usb: dwc3: gadget: Don't prepare beyond a transfer
>   usb: dwc3: gadget: Handle stream transfers
>   usb: dwc3: gadget: Use SET_EP_PRIME for NoStream

This seris is now in testing/next. Can you check that everything looks
fine for you? I had to manually apply one patch.