queue-4.4/scsi-libsas-do-discovery-on-empty-phy-to-update-phy-.patch

   1 From b7b72a33e073279bcf55cc1d3a0f8550cd9d093b Mon Sep 17 00:00:00 2001
   2 From: John Garry <john.garry@huawei.com>
   3 Date: Fri, 12 Apr 2019 16:57:56 +0800
   4 Subject: scsi: libsas: Do discovery on empty PHY to update PHY info
   5
   6 [ Upstream commit d8649fc1c5e40e691d589ed825998c36a947491c ]
   7
   8 When we discover the PHY is empty in sas_rediscover_dev(), the PHY
   9 information (like negotiated linkrate) is not updated.
  10
  11 As such, for a user examining sysfs for that PHY, they would see
  12 incorrect values:
  13
  14 root@(none)$ cd /sys/class/sas_phy/phy-0:0:20
  15 root@(none)$ more negotiated_linkrate
  16 3.0 Gbit
  17 root@(none)$ echo 0 > enable
  18 root@(none)$ more negotiated_linkrate
  19 3.0 Gbit
  20
  21 So fix this, simply discover the PHY again, even though we know it's empty;
  22 in the above example, this gives us:
  23
  24 root@(none)$ more negotiated_linkrate
  25 Phy disabled
  26
  27 We must do this after unregistering the device associated with the PHY
  28 (in sas_unregister_devs_sas_addr()).
  29
  30 Signed-off-by: John Garry <john.garry@huawei.com>
  31 Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
  32 Signed-off-by: Sasha Levin <sashal@kernel.org>
  33 ---
  34  drivers/scsi/libsas/sas_expander.c | 5 +++++
  35  1 file changed, 5 insertions(+)
  36
  37 diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
  38 index 1a6f65db615e8..ee1f9ee995e53 100644
  39 --- a/drivers/scsi/libsas/sas_expander.c
  40 +++ b/drivers/scsi/libsas/sas_expander.c
  41 @@ -2027,6 +2027,11 @@ static int sas_rediscover_dev(struct domain_device *dev, int phy_id, bool last)
  42         if ((SAS_ADDR(sas_addr) == 0) || (res == -ECOMM)) {
  43                 phy->phy_state = PHY_EMPTY;
  44                 sas_unregister_devs_sas_addr(dev, phy_id, last);
  45 +               /*
  46 +                * Even though the PHY is empty, for convenience we discover
  47 +                * the PHY to update the PHY info, like negotiated linkrate.
  48 +                */
  49 +               sas_ex_phy_discover(dev, phy_id);
  50                 return res;
  51         } else if (SAS_ADDR(sas_addr) == SAS_ADDR(phy->attached_sas_addr) &&
  52                    dev_type_flutter(type, phy->attached_dev_type)) {
  53 --
  54 2.20.1
  55