target/linux/octeontx/patches-4.14/0001-net-thunderx-workaround-BGX-TX-Underflow-issue.patch

   1 From b1e7791e688620c9bb8476ac2d0bc99abeb7f825 Mon Sep 17 00:00:00 2001
   2 From: Tim Harvey <tharvey@gateworks.com>
   3 Date: Fri, 29 Dec 2017 16:48:04 -0800
   4 Subject: [PATCH] net: thunderx: workaround BGX TX Underflow issue
   5
   6 While it is not yet understood why a TX underflow can easily occur
   7 for SGMII interfaces resulting in a TX wedge. It has been found that
   8 disabling/re-enabling the LMAC resolves the issue.
   9
  10 Signed-off-by: Tim Harvey <tharvey@gateworks.com>
  11 ---
  12  drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 54 +++++++++++++++++++++++
  13  drivers/net/ethernet/cavium/thunder/thunder_bgx.h |  9 ++++
  14  2 files changed, 63 insertions(+)
  15
  16 --- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
  17 +++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
  18 @@ -56,6 +56,7 @@ struct bgx {
  19         bool                    is_dlm;
  20         bool                    is_rgx;
  21         int                     phy_mode;
  22 +       char                    irq_name[7];
  23  };
  24
  25  static struct bgx *bgx_vnic[MAX_BGX_THUNDER];
  26 @@ -1344,6 +1345,53 @@ static int bgx_init_phy(struct bgx *bgx)
  27         return bgx_init_of_phy(bgx);
  28  }
  29
  30 +static irqreturn_t bgx_intr_handler(int irq, void *data)
  31 +{
  32 +       struct bgx *bgx = (struct bgx *)data;
  33 +       struct device *dev = &bgx->pdev->dev;
  34 +       u64 status, val;
  35 +       int lmac;
  36 +
  37 +       for (lmac = 0; lmac < bgx->lmac_count; lmac++) {
  38 +               status = bgx_reg_read(bgx, lmac, BGX_GMP_GMI_TXX_INT);
  39 +               if (status & GMI_TXX_INT_UNDFLW) {
  40 +                       dev_err(dev, "BGX%d lmac%d UNDFLW\n", bgx->bgx_id,
  41 +                               lmac);
  42 +                       val = bgx_reg_read(bgx, lmac, BGX_CMRX_CFG);
  43 +                       val &= ~CMR_EN;
  44 +                       bgx_reg_write(bgx, lmac, BGX_CMRX_CFG, val);
  45 +                       val |= CMR_EN;
  46 +                       bgx_reg_write(bgx, lmac, BGX_CMRX_CFG, val);
  47 +               }
  48 +               /* clear interrupts */
  49 +               bgx_reg_write(bgx, lmac, BGX_GMP_GMI_TXX_INT, status);
  50 +       }
  51 +
  52 +       return IRQ_HANDLED;
  53 +}
  54 +
  55 +static int bgx_register_intr(struct pci_dev *pdev)
  56 +{
  57 +       struct bgx *bgx = pci_get_drvdata(pdev);
  58 +       struct device *dev = &pdev->dev;
  59 +       int num_vec, ret;
  60 +
  61 +       /* Enable MSI-X */
  62 +       num_vec = pci_msix_vec_count(pdev);
  63 +       ret = pci_alloc_irq_vectors(pdev, num_vec, num_vec, PCI_IRQ_MSIX);
  64 +       if (ret < 0) {
  65 +               dev_err(dev, "Req for #%d msix vectors failed\n", num_vec);
  66 +               return 1;
  67 +       }
  68 +       sprintf(bgx->irq_name, "BGX%d", bgx->bgx_id);
  69 +       ret = request_irq(pci_irq_vector(pdev, GMPX_GMI_TX_INT),
  70 +               bgx_intr_handler, 0, bgx->irq_name, bgx);
  71 +       if (ret)
  72 +               return 1;
  73 +
  74 +       return 0;
  75 +}
  76 +
  77  static int bgx_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
  78  {
  79         int err;
  80 @@ -1414,6 +1462,8 @@ static int bgx_probe(struct pci_dev *pde
  81                 xcv_init_hw(bgx->phy_mode);
  82         bgx_init_hw(bgx);
  83
  84 +       bgx_register_intr(pdev);
  85 +
  86         /* Enable all LMACs */
  87         for (lmac = 0; lmac < bgx->lmac_count; lmac++) {
  88                 err = bgx_lmac_enable(bgx, lmac);
  89 @@ -1424,6 +1474,10 @@ static int bgx_probe(struct pci_dev *pde
  90                                 bgx_lmac_disable(bgx, --lmac);
  91                         goto err_enable;
  92                 }
  93 +
  94 +               /* enable TX FIFO Underflow interrupt */
  95 +               bgx_reg_modify(bgx, lmac, BGX_GMP_GMI_TXX_INT_ENA_W1S,
  96 +                              GMI_TXX_INT_UNDFLW);
  97         }
  98
  99         return 0;
 100 --- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.h
 101 +++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.h
 102 @@ -179,6 +179,15 @@
 103  #define BGX_GMP_GMI_TXX_BURST          0x38228
 104  #define BGX_GMP_GMI_TXX_MIN_PKT                0x38240
 105  #define BGX_GMP_GMI_TXX_SGMII_CTL      0x38300
 106 +#define BGX_GMP_GMI_TXX_INT            0x38500
 107 +#define BGX_GMP_GMI_TXX_INT_W1S                0x38508
 108 +#define BGX_GMP_GMI_TXX_INT_ENA_W1C    0x38510
 109 +#define BGX_GMP_GMI_TXX_INT_ENA_W1S    0x38518
 110 +#define  GMI_TXX_INT_PTP_LOST                  BIT_ULL(4)
 111 +#define  GMI_TXX_INT_LATE_COL                  BIT_ULL(3)
 112 +#define  GMI_TXX_INT_XSDEF                     BIT_ULL(2)
 113 +#define  GMI_TXX_INT_XSCOL                     BIT_ULL(1)
 114 +#define  GMI_TXX_INT_UNDFLW                    BIT_ULL(0)
 115
 116  #define BGX_MSIX_VEC_0_29_ADDR         0x400000 /* +(0..29) << 4 */
 117  #define BGX_MSIX_VEC_0_29_CTL          0x400008