target/linux/mvebu/patches-4.14/524-PCI-aardvark-set-host-and-device-to-the-same-MAX-payload-size.patch

   1 From patchwork Thu Sep 28 12:58:34 2017
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   5 Subject: [v2,
   6  3/7] PCI: aardvark: set host and device to the same MAX payload size
   7 X-Patchwork-Submitter: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
   8 X-Patchwork-Id: 819587
   9 Message-Id: <20170928125838.11887-4-thomas.petazzoni@free-electrons.com>
  10 To: Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org
  11 Cc: Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>,
  12  Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>, Gregory Clement
  13  <gregory.clement@free-electrons.com>,
  14  Nadav Haklai <nadavh@marvell.com>, Hanna Hawa <hannah@marvell.com>,
  15  Yehuda Yitschak <yehuday@marvell.com>,
  16  linux-arm-kernel@lists.infradead.org, Antoine Tenart
  17  <antoine.tenart@free-electrons.com>, =?utf-8?q?Miqu=C3=A8l_Raynal?=
  18  <miquel.raynal@free-electrons.com>, Victor Gu <xigu@marvell.com>,
  19  Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  20 Date: Thu, 28 Sep 2017 14:58:34 +0200
  21 From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  22 List-Id: <linux-pci.vger.kernel.org>
  23
  24 From: Victor Gu <xigu@marvell.com>
  25
  26 Since the Aardvark does not implement a PCIe root bus, the Linux PCIe
  27 subsystem will not align the MAX payload size between the host and the
  28 device. This patch ensures that the host and device have the same MAX
  29 payload size, fixing a number of problems with various PCIe devices.
  30
  31 This is part of fixing bug
  32 https://bugzilla.kernel.org/show_bug.cgi?id=196339, this commit was
  33 reported as the user to be important to get a Intel 7260 mini-PCIe
  34 WiFi card working.
  35
  36 Fixes: Fixes: 8c39d710363c1 ("PCI: aardvark: Add Aardvark PCI host controller driver")
  37 Signed-off-by: Victor Gu <xigu@marvell.com>
  38 Reviewed-by: Evan Wang <xswang@marvell.com>
  39 Reviewed-by: Nadav Haklai <nadavh@marvell.com>
  40 [Thomas: tweak commit log.]
  41 Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  42 ---
  43  drivers/pci/host/pci-aardvark.c | 60 ++++++++++++++++++++++++++++++++++++++++-
  44  1 file changed, 59 insertions(+), 1 deletion(-)
  45
  46 --- a/drivers/pci/host/pci-aardvark.c
  47 +++ b/drivers/pci/host/pci-aardvark.c
  48 @@ -30,8 +30,10 @@
  49  #define PCIE_CORE_DEV_CTRL_STATS_REG                           0xc8
  50  #define     PCIE_CORE_DEV_CTRL_STATS_RELAX_ORDER_DISABLE       (0 << 4)
  51  #define     PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ_SHIFT      5
  52 +#define     PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ            0x2
  53  #define     PCIE_CORE_DEV_CTRL_STATS_SNOOP_DISABLE             (0 << 11)
  54  #define     PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SIZE_SHIFT     12
  55 +#define     PCIE_CORE_MPS_UNIT_BYTE                            128
  56  #define PCIE_CORE_LINK_CTRL_STAT_REG                           0xd0
  57  #define     PCIE_CORE_LINK_L0S_ENTRY                           BIT(0)
  58  #define     PCIE_CORE_LINK_TRAINING                            BIT(5)
  59 @@ -297,7 +299,8 @@ static void advk_pcie_setup_hw(struct ad
  60
  61         /* Set PCIe Device Control and Status 1 PF0 register */
  62         reg = PCIE_CORE_DEV_CTRL_STATS_RELAX_ORDER_DISABLE |
  63 -               (7 << PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ_SHIFT) |
  64 +               (PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ <<
  65 +                PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ_SHIFT) |
  66                 PCIE_CORE_DEV_CTRL_STATS_SNOOP_DISABLE |
  67                 PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SIZE_SHIFT;
  68         advk_writel(pcie, reg, PCIE_CORE_DEV_CTRL_STATS_REG);
  69 @@ -879,6 +882,58 @@ out_release_res:
  70         return err;
  71  }
  72
  73 +static int advk_pcie_find_smpss(struct pci_dev *dev, void *data)
  74 +{
  75 +       u8 *smpss = data;
  76 +
  77 +       if (!dev)
  78 +               return 0;
  79 +
  80 +       if (!pci_is_pcie(dev))
  81 +               return 0;
  82 +
  83 +       if (*smpss > dev->pcie_mpss)
  84 +               *smpss = dev->pcie_mpss;
  85 +
  86 +       return 0;
  87 +}
  88 +
  89 +static int advk_pcie_bus_configure_mps(struct pci_dev *dev, void *data)
  90 +{
  91 +       int mps;
  92 +
  93 +       if (!dev)
  94 +               return 0;
  95 +
  96 +       if (!pci_is_pcie(dev))
  97 +               return 0;
  98 +
  99 +       mps = PCIE_CORE_MPS_UNIT_BYTE << *(u8 *)data;
 100 +       pcie_set_mps(dev, mps);
 101 +
 102 +       return 0;
 103 +}
 104 +
 105 +static void advk_pcie_configure_mps(struct pci_bus *bus, struct advk_pcie *pcie)
 106 +{
 107 +       u8 smpss = PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ;
 108 +       u32 reg;
 109 +
 110 +       /* Find the minimal supported MAX payload size */
 111 +       advk_pcie_find_smpss(bus->self, &smpss);
 112 +       pci_walk_bus(bus, advk_pcie_find_smpss, &smpss);
 113 +
 114 +       /* Configure RC MAX payload size */
 115 +       reg = advk_readl(pcie, PCIE_CORE_DEV_CTRL_STATS_REG);
 116 +       reg &= ~PCI_EXP_DEVCTL_PAYLOAD;
 117 +       reg |= smpss << PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ_SHIFT;
 118 +       advk_writel(pcie, reg, PCIE_CORE_DEV_CTRL_STATS_REG);
 119 +
 120 +       /* Configure device MAX payload size */
 121 +       advk_pcie_bus_configure_mps(bus->self, &smpss);
 122 +       pci_walk_bus(bus, advk_pcie_bus_configure_mps, &smpss);
 123 +}
 124 +
 125  static int advk_pcie_probe(struct platform_device *pdev)
 126  {
 127         struct device *dev = &pdev->dev;
 128 @@ -952,6 +1007,9 @@ static int advk_pcie_probe(struct platfo
 129         list_for_each_entry(child, &bus->children, node)
 130                 pcie_bus_configure_settings(child);
 131
 132 +       /* Configure the MAX pay load size */
 133 +       advk_pcie_configure_mps(bus, pcie);
 134 +
 135         pci_bus_add_devices(bus);
 136         return 0;
 137  }