queue-4.19/pci-pciehp-ignore-link-state-changes-after-powering-off-a-slot.patch

   1 From 3943af9d01e94330d0cfac6fccdbc829aad50c92 Mon Sep 17 00:00:00 2001
   2 From: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
   3 Date: Tue, 12 Mar 2019 15:05:48 +0300
   4 Subject: PCI: pciehp: Ignore Link State Changes after powering off a slot
   5
   6 From: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
   7
   8 commit 3943af9d01e94330d0cfac6fccdbc829aad50c92 upstream.
   9
  10 During a safe hot remove, the OS powers off the slot, which may cause a
  11 Data Link Layer State Changed event.  The slot has already been set to
  12 OFF_STATE, so that event results in re-enabling the device, making it
  13 impossible to safely remove it.
  14
  15 Clear out the Presence Detect Changed and Data Link Layer State Changed
  16 events when the disabled slot has settled down.
  17
  18 It is still possible to re-enable the device if it remains in the slot
  19 after pressing the Attention Button by pressing it again.
  20
  21 Fixes the problem that Micah reported below: an NVMe drive power button may
  22 not actually turn off the drive.
  23
  24 Link: https://bugzilla.kernel.org/show_bug.cgi?id=203237
  25 Reported-by: Micah Parrish <micah.parrish@hpe.com>
  26 Tested-by: Micah Parrish <micah.parrish@hpe.com>
  27 Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
  28 [bhelgaas: changelog, add bugzilla URL]
  29 Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  30 Reviewed-by: Lukas Wunner <lukas@wunner.de>
  31 Cc: stable@vger.kernel.org      # v4.19+
  32 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  33
  34 ---
  35  drivers/pci/hotplug/pciehp_ctrl.c |    4 ++++
  36  1 file changed, 4 insertions(+)
  37
  38 --- a/drivers/pci/hotplug/pciehp_ctrl.c
  39 +++ b/drivers/pci/hotplug/pciehp_ctrl.c
  40 @@ -117,6 +117,10 @@ static void remove_board(struct slot *p_
  41                  * removed from the slot/adapter.
  42                  */
  43                 msleep(1000);
  44 +
  45 +               /* Ignore link or presence changes caused by power off */
  46 +               atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
  47 +                          &ctrl->pending_events);
  48         }
  49
  50         /* turn off Green LED */