target/linux/brcm2708/patches-3.18/0046-fiq_fsm-Implement-hack-for-Split-Interrupt-transacti.patch

   1 From 099581aeb11b7eafbca02c9e69f6e6c8de0c57ec Mon Sep 17 00:00:00 2001
   2 From: P33M <P33M@github.com>
   3 Date: Fri, 20 Jun 2014 17:23:20 +0100
   4 Subject: [PATCH 046/114] fiq_fsm: Implement hack for Split Interrupt
   5  transactions
   6
   7 Hubs aren't too picky about which endpoint we send Control type split
   8 transactions to. By treating Interrupt transfers as Control, it is
   9 possible to use the non-periodic queue in the OTG core as well as the
  10 non-periodic FIFOs in the hub itself. This massively reduces the
  11 microframe exclusivity/contention that periodic split transactions
  12 otherwise have to enforce.
  13
  14 It goes without saying that this is a fairly egregious USB specification
  15 violation, but it works.
  16
  17 Original idea by Hans Petter Selasky @ FreeBSD.org.
  18 ---
  19  drivers/usb/host/dwc_otg/dwc_otg_hcd.c | 32 ++++++++++++++++++++++++++------
  20  1 file changed, 26 insertions(+), 6 deletions(-)
  21
  22 diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
  23 index 130096b..68d4f3b 100644
  24 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
  25 +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
  26 @@ -1055,10 +1055,11 @@ int dwc_otg_hcd_init(dwc_otg_hcd_t * hcd, dwc_otg_core_if_t * core_if)
  27                         for (i=0; i < hcd->core_if->core_params->host_channels; i++) {
  28                                 dwc_otg_cleanup_fiq_channel(hcd, i);
  29                         }
  30 -                       DWC_PRINTF("FIQ FSM acceleration enabled for :\n%s%s%s",
  31 +                       DWC_PRINTF("FIQ FSM acceleration enabled for :\n%s%s%s%s",
  32                                 (fiq_fsm_mask & 0x1) ? "Non-periodic Split Transactions\n" : "",
  33                                 (fiq_fsm_mask & 0x2) ? "Periodic Split Transactions\n" : "",
  34 -                               (fiq_fsm_mask & 0x4) ? "High-Speed Isochronous Endpoints\n" : "");
  35 +                               (fiq_fsm_mask & 0x4) ? "High-Speed Isochronous Endpoints\n" : "",
  36 +                               (fiq_fsm_mask & 0x8) ? "Interrupt/Control Split Transaction hack enabled\n" : "");
  37                 }
  38         }
  39
  40 @@ -1789,6 +1790,20 @@ int fiq_fsm_queue_split_transaction(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
  41         st->hcintmsk_copy.b.chhltd = 1;
  42         st->hcintmsk_copy.b.ahberr = 1;
  43
  44 +       /* Hack courtesy of FreeBSD: apparently forcing Interrupt Split transactions
  45 +        * as Control puts the transfer into the non-periodic request queue and the
  46 +        * non-periodic handler in the hub. Makes things lots easier.
  47 +        */
  48 +       if ((fiq_fsm_mask & 0x8) && hc->ep_type == UE_INTERRUPT) {
  49 +               st->hcchar_copy.b.multicnt = 0;
  50 +               st->hcchar_copy.b.oddfrm = 0;
  51 +               st->hcchar_copy.b.eptype = UE_CONTROL;
  52 +               if (hc->align_buff) {
  53 +                       st->hcdma_copy.d32 = hc->align_buff;
  54 +               } else {
  55 +                       st->hcdma_copy.d32 = ((unsigned long) hc->xfer_buff & 0xFFFFFFFF);
  56 +               }
  57 +       }
  58         DWC_WRITE_REG32(&hc_regs->hcdma, st->hcdma_copy.d32);
  59         DWC_WRITE_REG32(&hc_regs->hctsiz, st->hctsiz_copy.d32);
  60         DWC_WRITE_REG32(&hc_regs->hcsplt, st->hcsplt_copy.d32);
  61 @@ -1842,6 +1857,9 @@ int fiq_fsm_queue_split_transaction(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
  62                         }
  63                 }
  64         }
  65 +       if ((fiq_fsm_mask & 0x8) && hc->ep_type == UE_INTERRUPT)
  66 +               start_immediate = 1;
  67 +
  68         fiq_print(FIQDBG_INT, hcd->fiq_state, "FSMQ %01d %01d", hc->hc_num, start_immediate);
  69         fiq_print(FIQDBG_INT, hcd->fiq_state, "%08d", hfnum.b.frrem);
  70         //fiq_print(FIQDBG_INT, hcd->fiq_state, "H:%02dP:%02d", hub_addr, port_addr);
  71 @@ -1873,11 +1891,13 @@ int fiq_fsm_queue_split_transaction(dwc_otg_hcd_t *hcd, dwc_otg_qh_t *qh)
  72                         }
  73                         break;
  74                 case UE_INTERRUPT:
  75 -                               if (start_immediate) {
  76 +                       if (fiq_fsm_mask & 0x8) {
  77 +                               st->fsm = FIQ_NP_SSPLIT_STARTED;
  78 +                       } else if (start_immediate) {
  79                                         st->fsm = FIQ_PER_SSPLIT_STARTED;
  80 -                               } else {
  81 -                                       st->fsm = FIQ_PER_SSPLIT_QUEUED;
  82 -                               }
  83 +                       } else {
  84 +                               st->fsm = FIQ_PER_SSPLIT_QUEUED;
  85 +                       }
  86                 default:
  87                         break;
  88         }
  89 --
  90 1.8.3.2
  91