target/linux/generic/backport-5.15/703-14-v5.17-net-phylink-use-legacy_pre_march2020.patch

   1 From 001f4261fe4d5ae710cf1f445b6cae6d9d3ae26e Mon Sep 17 00:00:00 2001
   2 From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
   3 Date: Thu, 9 Dec 2021 13:11:48 +0000
   4 Subject: [PATCH] net: phylink: use legacy_pre_march2020
   5
   6 Use the legacy flag to indicate whether we should operate in legacy
   7 mode. This allows us to stop using the presence of a PCS as an
   8 indicator to the age of the phylink user, and make PCS presence
   9 optional.
  10
  11 Legacy mode involves:
  12 1) calling mac_config() whenever the link comes up
  13 2) calling mac_config() whenever the inband advertisement changes,
  14    possibly followed by a call to mac_an_restart()
  15 3) making use of mac_an_restart()
  16 4) making use of mac_pcs_get_state()
  17
  18 All the above functionality was moved to a seperate "PCS" block of
  19 operations in March 2020.
  20
  21 Update the documents to indicate that the differences that this flag
  22 makes.
  23
  24 Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
  25 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  26 ---
  27  drivers/net/phy/phylink.c | 12 ++++++------
  28  include/linux/phylink.h   | 17 +++++++++++++++++
  29  2 files changed, 23 insertions(+), 6 deletions(-)
  30
  31 --- a/drivers/net/phy/phylink.c
  32 +++ b/drivers/net/phy/phylink.c
  33 @@ -777,7 +777,7 @@ static void phylink_mac_pcs_an_restart(s
  34             phylink_autoneg_inband(pl->cur_link_an_mode)) {
  35                 if (pl->pcs_ops)
  36                         pl->pcs_ops->pcs_an_restart(pl->pcs);
  37 -               else
  38 +               else if (pl->config->legacy_pre_march2020)
  39                         pl->mac_ops->mac_an_restart(pl->config);
  40         }
  41  }
  42 @@ -855,7 +855,7 @@ static int phylink_change_inband_advert(
  43         if (test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state))
  44                 return 0;
  45
  46 -       if (!pl->pcs_ops) {
  47 +       if (!pl->pcs_ops && pl->config->legacy_pre_march2020) {
  48                 /* Legacy method */
  49                 phylink_mac_config(pl, &pl->link_config);
  50                 phylink_mac_pcs_an_restart(pl);
  51 @@ -900,7 +900,8 @@ static void phylink_mac_pcs_get_state(st
  52
  53         if (pl->pcs_ops)
  54                 pl->pcs_ops->pcs_get_state(pl->pcs, state);
  55 -       else if (pl->mac_ops->mac_pcs_get_state)
  56 +       else if (pl->mac_ops->mac_pcs_get_state &&
  57 +                pl->config->legacy_pre_march2020)
  58                 pl->mac_ops->mac_pcs_get_state(pl->config, state);
  59         else
  60                 state->link = 0;
  61 @@ -1094,12 +1095,11 @@ static void phylink_resolve(struct work_
  62                         }
  63                         phylink_major_config(pl, false, &link_state);
  64                         pl->link_config.interface = link_state.interface;
  65 -               } else if (!pl->pcs_ops) {
  66 +               } else if (!pl->pcs_ops && pl->config->legacy_pre_march2020) {
  67                         /* The interface remains unchanged, only the speed,
  68                          * duplex or pause settings have changed. Call the
  69                          * old mac_config() method to configure the MAC/PCS
  70 -                        * only if we do not have a PCS installed (an
  71 -                        * unconverted user.)
  72 +                        * only if we do not have a legacy MAC driver.
  73                          */
  74                         phylink_mac_config(pl, &link_state);
  75                 }
  76 --- a/include/linux/phylink.h
  77 +++ b/include/linux/phylink.h
  78 @@ -210,6 +210,10 @@ struct phylink_pcs *mac_select_pcs(struc
  79   * negotiation completion state in @state->an_complete, and link up state
  80   * in @state->link. If possible, @state->lp_advertising should also be
  81   * populated.
  82 + *
  83 + * Note: This is a legacy method. This function will not be called unless
  84 + * legacy_pre_march2020 is set in &struct phylink_config and there is no
  85 + * PCS attached.
  86   */
  87  void mac_pcs_get_state(struct phylink_config *config,
  88                        struct phylink_link_state *state);
  89 @@ -250,6 +254,15 @@ int mac_prepare(struct phylink_config *c
  90   * guaranteed to be correct, and so any mac_config() implementation must
  91   * never reference these fields.
  92   *
  93 + * Note: For legacy March 2020 drivers (drivers with legacy_pre_march2020 set
  94 + * in their &phylnk_config and which don't have a PCS), this function will be
  95 + * called on each link up event, and to also change the in-band advert. For
  96 + * non-legacy drivers, it will only be called to reconfigure the MAC for a
  97 + * "major" change in e.g. interface mode. It will not be called for changes
  98 + * in speed, duplex or pause modes or to change the in-band advertisement.
  99 + * In any case, it is strongly preferred that speed, duplex and pause settings
 100 + * are handled in the mac_link_up() method and not in this method.
 101 + *
 102   * (this requires a rewrite - please refer to mac_link_up() for situations
 103   *  where the PCS and MAC are not tightly integrated.)
 104   *
 105 @@ -334,6 +347,10 @@ int mac_finish(struct phylink_config *co
 106  /**
 107   * mac_an_restart() - restart 802.3z BaseX autonegotiation
 108   * @config: a pointer to a &struct phylink_config.
 109 + *
 110 + * Note: This is a legacy method. This function will not be called unless
 111 + * legacy_pre_march2020 is set in &struct phylink_config and there is no
 112 + * PCS attached.
 113   */
 114  void mac_an_restart(struct phylink_config *config);
 115