target/linux/bcm27xx/patches-5.4/950-0394-dwc_otg-fiq_fsm-pause-when-cancelling-split-transact.patch

   1 From 09648b92a71b03450e9482f0cc5bd22298f78d44 Mon Sep 17 00:00:00 2001
   2 From: Jonathan Bell <jonathan@raspberrypi.org>
   3 Date: Wed, 8 Jan 2020 12:48:09 +0000
   4 Subject: [PATCH] dwc_otg: fiq_fsm: pause when cancelling split
   5  transactions
   6
   7 Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
   8 which may be freed immediately after the dequeue call returns. Block until
   9 we know the transfer is complete.
  10
  11 A similar delay is needed when cleaning up disconnects, as the FIQ could
  12 have started a periodic transfer in the previous microframe to the one
  13 that triggered a disconnect.
  14
  15 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
  16 ---
  17  drivers/usb/host/dwc_otg/dwc_otg_hcd.c    | 33 +++++++++++++++++++++--
  18  drivers/usb/host/dwc_otg/dwc_otg_os_dep.h |  1 +
  19  2 files changed, 32 insertions(+), 2 deletions(-)
  20
  21 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
  22 +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
  23 @@ -175,6 +175,7 @@ static void kill_urbs_in_qh_list(dwc_otg
  24         dwc_list_link_t *qh_item, *qh_tmp;
  25         dwc_otg_qh_t *qh;
  26         dwc_otg_qtd_t *qtd, *qtd_tmp;
  27 +       int quiesced = 0;
  28
  29         DWC_LIST_FOREACH_SAFE(qh_item, qh_tmp, qh_list) {
  30                 qh = DWC_LIST_ENTRY(qh_item, dwc_otg_qh_t, qh_list_entry);
  31 @@ -198,8 +199,17 @@ static void kill_urbs_in_qh_list(dwc_otg
  32                                 qh->channel->halt_status = DWC_OTG_HC_XFER_URB_DEQUEUE;
  33                                 qh->channel->halt_pending = 1;
  34                                 if (hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_TURBO ||
  35 -                                       hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
  36 +                                   hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
  37                                         hcd->fiq_state->channel[n].fsm = FIQ_HS_ISOC_ABORTED;
  38 +                               /* We're called from disconnect callback or in the middle of freeing the HCD here,
  39 +                                * so FIQ is disabled, top-level interrupts masked and we're holding the spinlock.
  40 +                                * No further URBs will be submitted, but wait 1 microframe for any previously
  41 +                                * submitted periodic DMA to finish.
  42 +                                */
  43 +                               if (!quiesced) {
  44 +                                       udelay(125);
  45 +                                       quiesced = 1;
  46 +                               }
  47                         } else {
  48                                 dwc_otg_hc_halt(hcd->core_if, qh->channel,
  49                                                 DWC_OTG_HC_XFER_URB_DEQUEUE);
  50 @@ -600,15 +610,34 @@ int dwc_otg_hcd_urb_dequeue(dwc_otg_hcd_
  51                         /* In FIQ FSM mode, we need to shut down carefully.
  52                          * The FIQ may attempt to restart a disabled channel */
  53                         if (fiq_fsm_enable && (hcd->fiq_state->channel[n].fsm != FIQ_PASSTHROUGH)) {
  54 +                               int retries = 3;
  55 +                               int running = 0;
  56 +                               enum fiq_fsm_state state;
  57 +
  58                                 local_fiq_disable();
  59                                 fiq_fsm_spin_lock(&hcd->fiq_state->lock);
  60                                 qh->channel->halt_status = DWC_OTG_HC_XFER_URB_DEQUEUE;
  61                                 qh->channel->halt_pending = 1;
  62                                 if (hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_TURBO ||
  63 -                                       hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
  64 +                                   hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
  65                                         hcd->fiq_state->channel[n].fsm = FIQ_HS_ISOC_ABORTED;
  66                                 fiq_fsm_spin_unlock(&hcd->fiq_state->lock);
  67                                 local_fiq_enable();
  68 +
  69 +                               if (dwc_qh_is_non_per(qh)) {
  70 +                                       do {
  71 +                                               state = READ_ONCE(hcd->fiq_state->channel[n].fsm);
  72 +                                               running = (state != FIQ_NP_SPLIT_DONE) &&
  73 +                                                         (state != FIQ_NP_SPLIT_LS_ABORTED) &&
  74 +                                                         (state != FIQ_NP_SPLIT_HS_ABORTED);
  75 +                                               if (!running)
  76 +                                                       break;
  77 +                                               udelay(125);
  78 +                                       } while(--retries);
  79 +                                       if (!retries)
  80 +                                               DWC_WARN("Timed out waiting for FSM NP transfer to complete on %d",
  81 +                                                        qh->channel->hc_num);
  82 +                               }
  83                         } else {
  84                                 dwc_otg_hc_halt(hcd->core_if, qh->channel,
  85                                                 DWC_OTG_HC_XFER_URB_DEQUEUE);
  86 --- a/drivers/usb/host/dwc_otg/dwc_otg_os_dep.h
  87 +++ b/drivers/usb/host/dwc_otg/dwc_otg_os_dep.h
  88 @@ -27,6 +27,7 @@
  89  #include <linux/workqueue.h>
  90  #include <linux/stat.h>
  91  #include <linux/pci.h>
  92 +#include <linux/compiler.h>
  93
  94  #include <linux/version.h>
  95