target/linux/generic/backport-5.15/703-15-v5.18-net-phy-phylink-fix-DSA-mac_select_pcs-introduction.patch

   1 From 1054457006d4a14de4ae4132030e33d7eedaeba1 Mon Sep 17 00:00:00 2001
   2 From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
   3 Date: Mon, 21 Feb 2022 17:10:52 +0000
   4 Subject: [PATCH] net: phy: phylink: fix DSA mac_select_pcs() introduction
   5
   6 Vladimir Oltean reports that probing on DSA drivers that aren't yet
   7 populating supported_interfaces now fails. Fix this by allowing
   8 phylink to detect whether DSA actually provides an underlying
   9 mac_select_pcs() implementation.
  10
  11 Reported-by: Vladimir Oltean <olteanv@gmail.com>
  12 Fixes: bde018222c6b ("net: dsa: add support for phylink mac_select_pcs()")
  13 Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
  14 Tested-by: Vladimir Oltean <olteanv@gmail.com>
  15 Link: https://lore.kernel.org/r/E1nMCD6-00A0wC-FG@rmk-PC.armlinux.org.uk
  16 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  17 ---
  18  drivers/net/phy/phylink.c | 14 +++++++++++---
  19  net/dsa/port.c            |  2 +-
  20  2 files changed, 12 insertions(+), 4 deletions(-)
  21
  22 --- a/drivers/net/phy/phylink.c
  23 +++ b/drivers/net/phy/phylink.c
  24 @@ -74,6 +74,7 @@ struct phylink {
  25         struct work_struct resolve;
  26
  27         bool mac_link_dropped;
  28 +       bool using_mac_select_pcs;
  29
  30         struct sfp_bus *sfp_bus;
  31         bool sfp_may_have_phy;
  32 @@ -163,7 +164,7 @@ static int phylink_validate_mac_and_pcs(
  33         int ret;
  34
  35         /* Get the PCS for this interface mode */
  36 -       if (pl->mac_ops->mac_select_pcs) {
  37 +       if (pl->using_mac_select_pcs) {
  38                 pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
  39                 if (IS_ERR(pcs))
  40                         return PTR_ERR(pcs);
  41 @@ -790,7 +791,7 @@ static void phylink_major_config(struct
  42
  43         phylink_dbg(pl, "major config %s\n", phy_modes(state->interface));
  44
  45 -       if (pl->mac_ops->mac_select_pcs) {
  46 +       if (pl->using_mac_select_pcs) {
  47                 pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
  48                 if (IS_ERR(pcs)) {
  49                         phylink_err(pl,
  50 @@ -1192,11 +1193,17 @@ struct phylink *phylink_create(struct ph
  51                                phy_interface_t iface,
  52                                const struct phylink_mac_ops *mac_ops)
  53  {
  54 +       bool using_mac_select_pcs = false;
  55         struct phylink *pl;
  56         int ret;
  57
  58 -       /* Validate the supplied configuration */
  59         if (mac_ops->mac_select_pcs &&
  60 +           mac_ops->mac_select_pcs(config, PHY_INTERFACE_MODE_NA) !=
  61 +             ERR_PTR(-EOPNOTSUPP))
  62 +               using_mac_select_pcs = true;
  63 +
  64 +       /* Validate the supplied configuration */
  65 +       if (using_mac_select_pcs &&
  66             phy_interface_empty(config->supported_interfaces)) {
  67                 dev_err(config->dev,
  68                         "phylink: error: empty supported_interfaces but mac_select_pcs() method present\n");
  69 @@ -1220,6 +1227,7 @@ struct phylink *phylink_create(struct ph
  70                 return ERR_PTR(-EINVAL);
  71         }
  72
  73 +       pl->using_mac_select_pcs = using_mac_select_pcs;
  74         pl->phy_state.interface = iface;
  75         pl->link_interface = iface;
  76         if (iface == PHY_INTERFACE_MODE_MOCA)
  77 --- a/net/dsa/port.c
  78 +++ b/net/dsa/port.c
  79 @@ -1033,8 +1033,8 @@ dsa_port_phylink_mac_select_pcs(struct p
  80                                 phy_interface_t interface)
  81  {
  82         struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
  83 +       struct phylink_pcs *pcs = ERR_PTR(-EOPNOTSUPP);
  84         struct dsa_switch *ds = dp->ds;
  85 -       struct phylink_pcs *pcs = NULL;
  86
  87         if (ds->ops->phylink_mac_select_pcs)
  88                 pcs = ds->ops->phylink_mac_select_pcs(ds, dp->index, interface);