1. 03 Jul, 2017 1 commit
    • Shawn Lin's avatar
      PCI: rockchip: Use normal register bank for config accessors · dc8cca5e
      Shawn Lin authored
      Rockchip's RC has two banks of registers for the root port: a normal bank
      that is strictly compatible with the PCIe spec, and a privileged bank that
      can be used to change RO bits of root port registers.
      
      When probing the RC driver, we use the privileged bank to do some basic
      setup work as some RO bits are hw-inited to wrong value.  But we didn't
      change to the normal bank after probing the driver.
      
      This leads to a serious problem when the PME code tries to clear the PME
      status by writing PCI_EXP_RTSTA_PME to the register of PCI_EXP_RTSTA.  Per
      PCIe 3.0 spec, section 7.8.14, the PME status bit is RW1C.  So the PME code
      is doing the right thing to clear the PME status but we find the RC doesn't
      clear it but actually setting it to one.  So finally the system trap in
      pcie_pme_work_fn() as PCI_EXP_RTSTA_PME is true now forever.  This issue
      can be reproduced by booting kernel with pci=nomsi.
      
      Use the normal register bank for the PCI config accessors.  The privileged
      bank is used only internally by this driver.
      
      Fixes: e77f847d ("PCI: rockchip: Add Rockchip PCIe controller support")
      Signed-off-by: default avatarShawn Lin <shawn.lin@rock-chips.com>
      Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
      Cc: stable@vger.kernel.org
      Cc: Jeffy Chen <jeffy.chen@rock-chips.com>
      Cc: Brian Norris <briannorris@chromium.org>
      dc8cca5e
  2. 02 Jul, 2017 39 commits