package/kernel/mac80211/patches/347-brcmfmac-Add-necessary-memory-barriers-for-SDIO.patch

   1 From: Hante Meuleman <meuleman@broadcom.com>
   2 Date: Wed, 18 Mar 2015 13:25:22 +0100
   3 Subject: [PATCH] brcmfmac: Add necessary memory barriers for SDIO.
   4
   5 SDIO uses a thread to handle all communication with the device,
   6 for this data is exchanged between threads. This data needs proper
   7 memory barriers to make sure that data "exchange" is going correct.
   8
   9 Reviewed-by: Arend Van Spriel <arend@broadcom.com>
  10 Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
  11 Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
  12 Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
  13 Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
  14 Signed-off-by: Arend van Spriel <arend@broadcom.com>
  15 Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
  16 ---
  17
  18 --- a/drivers/net/wireless/brcm80211/brcmfmac/sdio.c
  19 +++ b/drivers/net/wireless/brcm80211/brcmfmac/sdio.c
  20 @@ -507,8 +507,8 @@ struct brcmf_sdio {
  21
  22         struct workqueue_struct *brcmf_wq;
  23         struct work_struct datawork;
  24 -       atomic_t dpc_tskcnt;
  25 -       atomic_t dpc_running;
  26 +       bool dpc_triggered;
  27 +       bool dpc_running;
  28
  29         bool txoff;             /* Transmit flow-controlled */
  30         struct brcmf_sdio_count sdcnt;
  31 @@ -2713,6 +2713,7 @@ static void brcmf_sdio_dpc(struct brcmf_
  32                         err = brcmf_sdio_tx_ctrlframe(bus,  bus->ctrl_frame_buf,
  33                                                       bus->ctrl_frame_len);
  34                         bus->ctrl_frame_err = err;
  35 +                       wmb();
  36                         bus->ctrl_frame_stat = false;
  37                 }
  38                 sdio_release_host(bus->sdiodev->func[1]);
  39 @@ -2734,6 +2735,7 @@ static void brcmf_sdio_dpc(struct brcmf_
  40                         sdio_claim_host(bus->sdiodev->func[1]);
  41                         if (bus->ctrl_frame_stat) {
  42                                 bus->ctrl_frame_err = -ENODEV;
  43 +                               wmb();
  44                                 bus->ctrl_frame_stat = false;
  45                                 brcmf_sdio_wait_event_wakeup(bus);
  46                         }
  47 @@ -2744,7 +2746,7 @@ static void brcmf_sdio_dpc(struct brcmf_
  48                    (!atomic_read(&bus->fcstate) &&
  49                     brcmu_pktq_mlen(&bus->txq, ~bus->flowcontrol) &&
  50                     data_ok(bus))) {
  51 -               atomic_inc(&bus->dpc_tskcnt);
  52 +               bus->dpc_triggered = true;
  53         }
  54  }
  55
  56 @@ -2940,6 +2942,7 @@ brcmf_sdio_bus_txctl(struct device *dev,
  57         /* Send from dpc */
  58         bus->ctrl_frame_buf = msg;
  59         bus->ctrl_frame_len = msglen;
  60 +       wmb();
  61         bus->ctrl_frame_stat = true;
  62
  63         brcmf_sdio_trigger_dpc(bus);
  64 @@ -2958,6 +2961,7 @@ brcmf_sdio_bus_txctl(struct device *dev,
  65         if (!ret) {
  66                 brcmf_dbg(SDIO, "ctrl_frame complete, err=%d\n",
  67                           bus->ctrl_frame_err);
  68 +               rmb();
  69                 ret = bus->ctrl_frame_err;
  70         }
  71
  72 @@ -3526,8 +3530,8 @@ done:
  73
  74  void brcmf_sdio_trigger_dpc(struct brcmf_sdio *bus)
  75  {
  76 -       if (atomic_read(&bus->dpc_tskcnt) == 0) {
  77 -               atomic_inc(&bus->dpc_tskcnt);
  78 +       if (!bus->dpc_triggered) {
  79 +               bus->dpc_triggered = true;
  80                 queue_work(bus->brcmf_wq, &bus->datawork);
  81         }
  82  }
  83 @@ -3558,7 +3562,7 @@ void brcmf_sdio_isr(struct brcmf_sdio *b
  84         if (!bus->intr)
  85                 brcmf_err("isr w/o interrupt configured!\n");
  86
  87 -       atomic_inc(&bus->dpc_tskcnt);
  88 +       bus->dpc_triggered = true;
  89         queue_work(bus->brcmf_wq, &bus->datawork);
  90  }
  91
  92 @@ -3578,7 +3582,7 @@ static void brcmf_sdio_bus_watchdog(stru
  93                 if (!bus->intr ||
  94                     (bus->sdcnt.intrcount == bus->sdcnt.lastintrs)) {
  95
  96 -                       if (atomic_read(&bus->dpc_tskcnt) == 0) {
  97 +                       if (!bus->dpc_triggered) {
  98                                 u8 devpend;
  99
 100                                 sdio_claim_host(bus->sdiodev->func[1]);
 101 @@ -3596,7 +3600,7 @@ static void brcmf_sdio_bus_watchdog(stru
 102                                 bus->sdcnt.pollcnt++;
 103                                 atomic_set(&bus->ipend, 1);
 104
 105 -                               atomic_inc(&bus->dpc_tskcnt);
 106 +                               bus->dpc_triggered = true;
 107                                 queue_work(bus->brcmf_wq, &bus->datawork);
 108                         }
 109                 }
 110 @@ -3623,17 +3627,21 @@ static void brcmf_sdio_bus_watchdog(stru
 111  #endif                         /* DEBUG */
 112
 113         /* On idle timeout clear activity flag and/or turn off clock */
 114 -       if ((atomic_read(&bus->dpc_tskcnt) == 0) &&
 115 -           (atomic_read(&bus->dpc_running) == 0) &&
 116 -           (bus->idletime > 0) && (bus->clkstate == CLK_AVAIL)) {
 117 -               bus->idlecount++;
 118 -               if (bus->idlecount > bus->idletime) {
 119 -                       brcmf_dbg(SDIO, "idle\n");
 120 -                       sdio_claim_host(bus->sdiodev->func[1]);
 121 -                       brcmf_sdio_wd_timer(bus, 0);
 122 +       if (!bus->dpc_triggered) {
 123 +               rmb();
 124 +               if ((!bus->dpc_running) && (bus->idletime > 0) &&
 125 +                   (bus->clkstate == CLK_AVAIL)) {
 126 +                       bus->idlecount++;
 127 +                       if (bus->idlecount > bus->idletime) {
 128 +                               brcmf_dbg(SDIO, "idle\n");
 129 +                               sdio_claim_host(bus->sdiodev->func[1]);
 130 +                               brcmf_sdio_wd_timer(bus, 0);
 131 +                               bus->idlecount = 0;
 132 +                               brcmf_sdio_bus_sleep(bus, true, false);
 133 +                               sdio_release_host(bus->sdiodev->func[1]);
 134 +                       }
 135 +               } else {
 136                         bus->idlecount = 0;
 137 -                       brcmf_sdio_bus_sleep(bus, true, false);
 138 -                       sdio_release_host(bus->sdiodev->func[1]);
 139                 }
 140         } else {
 141                 bus->idlecount = 0;
 142 @@ -3645,13 +3653,14 @@ static void brcmf_sdio_dataworker(struct
 143         struct brcmf_sdio *bus = container_of(work, struct brcmf_sdio,
 144                                               datawork);
 145
 146 -       while (atomic_read(&bus->dpc_tskcnt)) {
 147 -               atomic_set(&bus->dpc_running, 1);
 148 -               atomic_set(&bus->dpc_tskcnt, 0);
 149 +       bus->dpc_running = true;
 150 +       wmb();
 151 +       while (ACCESS_ONCE(bus->dpc_triggered)) {
 152 +               bus->dpc_triggered = false;
 153                 brcmf_sdio_dpc(bus);
 154                 bus->idlecount = 0;
 155 -               atomic_set(&bus->dpc_running, 0);
 156         }
 157 +       bus->dpc_running = false;
 158         if (brcmf_sdiod_freezing(bus->sdiodev)) {
 159                 brcmf_sdiod_change_state(bus->sdiodev, BRCMF_SDIOD_DOWN);
 160                 brcmf_sdiod_try_freeze(bus->sdiodev);
 161 @@ -4144,8 +4153,8 @@ struct brcmf_sdio *brcmf_sdio_probe(stru
 162                 bus->watchdog_tsk = NULL;
 163         }
 164         /* Initialize DPC thread */
 165 -       atomic_set(&bus->dpc_tskcnt, 0);
 166 -       atomic_set(&bus->dpc_running, 0);
 167 +       bus->dpc_triggered = false;
 168 +       bus->dpc_running = false;
 169
 170         /* Assign bus interface call back */
 171         bus->sdiodev->bus_if->dev = bus->sdiodev->dev;