target/linux/bcm53xx/patches-4.1/820-xhci-add-Broadcom-specific-fake-doorbell.patch

   1 From 9cc14ca0aae53c16d10ffea49848ac61a5015562 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
   3 Date: Sun, 21 Jun 2015 11:10:49 +0200
   4 Subject: [PATCH] xhci: add Broadcom specific fake doorbell
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 This fixes problem with controller seeing devices only in some small
  10 percentage of cold boots.
  11
  12 Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
  13 ---
  14  drivers/usb/host/xhci.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++
  15  1 file changed, 62 insertions(+)
  16
  17 --- a/drivers/usb/host/xhci.c
  18 +++ b/drivers/usb/host/xhci.c
  19 @@ -121,6 +121,64 @@ int xhci_halt(struct xhci_hcd *xhci)
  20         return ret;
  21  }
  22
  23 +#ifdef CONFIG_ARCH_BCM_5301X
  24 +int xhci_fake_doorbell(struct xhci_hcd *xhci, int slot_id)
  25 +{
  26 +       unsigned int temp1, ret;
  27 +
  28 +       /* alloc a virt device for slot */
  29 +       if (!xhci_alloc_virt_device(xhci, slot_id, 0, GFP_NOIO)) {
  30 +               xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
  31 +               return 1;
  32 +        }
  33 +
  34 +       /* ring fake doorbell for slot_id ep 0 */
  35 +       xhci_ring_ep_doorbell(xhci, slot_id, 0, 0);
  36 +       mdelay(1);
  37 +
  38 +       /* read the status register to check if HSE is set or not? */
  39 +       temp1 = readl(&xhci->op_regs->status);
  40 +       xhci_dbg(xhci, "op reg status = %x\n",temp1);
  41 +
  42 +       /* clear HSE if set */
  43 +       if(temp1 & STS_FATAL) {
  44 +               xhci_dbg(xhci, "HSE problem detected\n");
  45 +               temp1 &= ~(0x1fff);
  46 +               temp1 |= STS_FATAL;
  47 +               xhci_dbg(xhci, "temp1=%x\n",temp1);
  48 +               writel(temp1, &xhci->op_regs->status);
  49 +               mdelay(1);
  50 +               temp1 = readl(&xhci->op_regs->status);
  51 +               xhci_dbg(xhci, "After clear op reg status=%x\n", temp1);
  52 +       }
  53 +
  54 +       /* Free virt device */
  55 +       xhci_free_virt_device(xhci, slot_id);
  56 +
  57 +       /* Run the controller if needed */
  58 +       temp1 = readl(&xhci->op_regs->command);
  59 +       if (temp1 & CMD_RUN)
  60 +               return 0;
  61 +       temp1 |= (CMD_RUN);
  62 +
  63 +       writel(temp1, &xhci->op_regs->command);
  64 +       /*
  65 +        * Wait for the HCHalted Status bit to be 0 to indicate the host is running.
  66 +        */
  67 +       ret = xhci_handshake(&xhci->op_regs->status,
  68 +                            STS_HALT, 0, XHCI_MAX_HALT_USEC);
  69 +
  70 +       if (ret == -ETIMEDOUT) {
  71 +               xhci_err(xhci, "Host took too long to start, "
  72 +                               "waited %u microseconds.\n",
  73 +                               XHCI_MAX_HALT_USEC);
  74 +               return 1;
  75 +       }
  76 +
  77 +       return 0;
  78 +}
  79 +#endif /* CONFIG_ARCH_BCM_5301X */
  80 +
  81  /*
  82   * Set the run bit and wait for the host to be running.
  83   */
  84 @@ -145,6 +203,10 @@ static int xhci_start(struct xhci_hcd *x
  85                 xhci_err(xhci, "Host took too long to start, "
  86                                 "waited %u microseconds.\n",
  87                                 XHCI_MAX_HALT_USEC);
  88 +#ifdef CONFIG_ARCH_BCM_5301X
  89 +       xhci_fake_doorbell(xhci, 1);
  90 +#endif /* CONFIG_ARCH_BCM_5301X */
  91 +
  92         if (!ret)
  93                 xhci->xhc_state &= ~XHCI_STATE_HALTED;
  94         return ret;