target/linux/bcm53xx/patches-4.4/088-PCI-iproc-Fix-BCMA-PCIe-bus-scanning-regression.patch

   1 From c43e4b52cbf2267047f67c9f65de18ee1ab8bfa2 Mon Sep 17 00:00:00 2001
   2 From: Ray Jui <rjui@broadcom.com>
   3 Date: Wed, 27 Jan 2016 16:52:24 -0600
   4 Subject: [PATCH] PCI: iproc: Fix BCMA PCIe bus scanning regression
   5
   6 Commit 943ebae781f5 ("PCI: iproc: Add PAXC interface support") causes
   7 regression on EP device detection on BCMA based platforms.
   8
   9 Fix the issue by allowing multiple devices to be configured on the same
  10 bus, for all PAXB based child buses.  In addition, add a check to prevent
  11 non-zero function from being used on bus 0 (root bus).
  12
  13 Fixes: 943ebae781f5 ("PCI: iproc: Add PAXC interface support")
  14 Reported-by: Rafal Milecki <zajec5@gmail.com>
  15 Signed-off-by: Ray Jui <rjui@broadcom.com>
  16 Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  17 ---
  18  drivers/pci/host/pcie-iproc.c | 28 +++++++++++-----------------
  19  1 file changed, 11 insertions(+), 17 deletions(-)
  20
  21 --- a/drivers/pci/host/pcie-iproc.c
  22 +++ b/drivers/pci/host/pcie-iproc.c
  23 @@ -170,20 +170,6 @@ static inline void iproc_pcie_ob_write(s
  24         writel(val, pcie->base + offset + (window * 8));
  25  }
  26
  27 -static inline bool iproc_pcie_device_is_valid(struct iproc_pcie *pcie,
  28 -                                             unsigned int slot,
  29 -                                             unsigned int fn)
  30 -{
  31 -       if (slot > 0)
  32 -               return false;
  33 -
  34 -       /* PAXC can only support limited number of functions */
  35 -       if (pcie->type == IPROC_PCIE_PAXC && fn >= MAX_NUM_PAXC_PF)
  36 -               return false;
  37 -
  38 -       return true;
  39 -}
  40 -
  41  /**
  42   * Note access to the configuration registers are protected at the higher layer
  43   * by 'pci_lock' in drivers/pci/access.c
  44 @@ -199,11 +185,11 @@ static void __iomem *iproc_pcie_map_cfg_
  45         u32 val;
  46         u16 offset;
  47
  48 -       if (!iproc_pcie_device_is_valid(pcie, slot, fn))
  49 -               return NULL;
  50 -
  51         /* root complex access */
  52         if (busno == 0) {
  53 +               if (slot > 0 || fn > 0)
  54 +                       return NULL;
  55 +
  56                 iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_IND_ADDR,
  57                                      where & CFG_IND_ADDR_MASK);
  58                 offset = iproc_pcie_reg_offset(pcie, IPROC_PCIE_CFG_IND_DATA);
  59 @@ -213,6 +199,14 @@ static void __iomem *iproc_pcie_map_cfg_
  60                         return (pcie->base + offset);
  61         }
  62
  63 +       /*
  64 +        * PAXC is connected to an internally emulated EP within the SoC.  It
  65 +        * allows only one device and supports a limited number of functions.
  66 +        */
  67 +       if (pcie->type == IPROC_PCIE_PAXC)
  68 +               if (slot > 0 || fn >= MAX_NUM_PAXC_PF)
  69 +                       return NULL;
  70 +
  71         /* EP device access */
  72         val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
  73                 (slot << CFG_ADDR_DEV_NUM_SHIFT) |