git.ipfire.org Git - thirdparty/openwrt.git/blob

   1 From 9d3afd87557637a37135aa6e370dea846b839c2d Mon Sep 17 00:00:00 2001
   2 From: Jonathan Bell <jonathan@raspberrypi.com>
   3 Date: Mon, 11 Nov 2024 10:30:38 +0000
   4 Subject: [PATCH] drivers: usb: xhci: set HID bit in streaming endpoint
   5  contexts
   6
   7 The xHC may commence Host Initiated Data Moves for streaming endpoints -
   8 see USB3.2 spec s8.12.1.4.2.4. However, this behaviour is typically
   9 counterproductive as the submission of UAS URBs in {Status, Data,
  10 Command} order and 1 outstanding IO per stream ID means the device never
  11 enters Move Data after a HIMD for Status or Data stages with the same
  12 stream ID. For OUT transfers this is especially inefficient as the host
  13 will start transmitting multiple bulk packets as a burst, all of which
  14 get NAKed by the device - wasting bandwidth.
  15
  16 Also, some buggy UAS adapters don't properly handle the EP flow control
  17 state this creates - e.g. RTL9210.
  18
  19 Set Host Initiated Data Move Disable to always defer stream selection to
  20 the device. xHC implementations may treat this field as "don't care,
  21 forced to 1" anyway - xHCI 1.2 s4.12.1.
  22
  23 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
  24 ---
  25  drivers/usb/host/xhci-mem.c | 8 ++++++++
  26  drivers/usb/host/xhci.h     | 2 ++
  27  2 files changed, 10 insertions(+)
  28
  29 --- a/drivers/usb/host/xhci-mem.c
  30 +++ b/drivers/usb/host/xhci-mem.c
  31 @@ -715,6 +715,14 @@ void xhci_setup_streams_ep_input_ctx(str
  32         ep_ctx->ep_info &= cpu_to_le32(~EP_MAXPSTREAMS_MASK);
  33         ep_ctx->ep_info |= cpu_to_le32(EP_MAXPSTREAMS(max_primary_streams)
  34                                        | EP_HAS_LSA);
  35 +
  36 +       /*
  37 +        * Set Host Initiated Data Move Disable to always defer stream
  38 +        * selection to the device. xHC implementations may treat this
  39 +        * field as "don't care, forced to 1" anyway - xHCI 1.2 s4.12.1.
  40 +        */
  41 +       ep_ctx->ep_info2 |= EP_HID;
  42 +
  43         ep_ctx->deq  = cpu_to_le64(stream_info->ctx_array_dma);
  44  }
  45
  46 --- a/drivers/usb/host/xhci.h
  47 +++ b/drivers/usb/host/xhci.h
  48 @@ -465,6 +465,8 @@ struct xhci_ep_ctx {
  49  #define CTX_TO_EP_MAXPSTREAMS(p)       (((p) & EP_MAXPSTREAMS_MASK) >> 10)
  50  /* Endpoint is set up with a Linear Stream Array (vs. Secondary Stream Array) */
  51  #define        EP_HAS_LSA              (1 << 15)
  52 +/* Host initiated data move disable in info2 */
  53 +#define EP_HID                 (1 << 7)
  54  /* hosts with LEC=1 use bits 31:24 as ESIT high bits. */
  55  #define CTX_TO_MAX_ESIT_PAYLOAD_HI(p)  (((p) >> 24) & 0xff)
  56