target/linux/generic/pending-5.15/723-net-mt7531-ensure-all-MACs-are-powered-down-before-r.patch

   1 From 3fb8841513c4ec3a2e5d366df86230c45f239a57 Mon Sep 17 00:00:00 2001
   2 From: Alexander Couzens <lynxis@fe80.eu>
   3 Date: Sat, 13 Aug 2022 13:08:22 +0200
   4 Subject: [PATCH 03/10] net: mt7531: ensure all MACs are powered down before
   5  reset
   6
   7 The datasheet [1] explicit describes it as requirement for a reset.
   8
   9 [1] MT7531 Reference Manual for Development Board rev 1.0, page 735
  10
  11 Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
  12 ---
  13  drivers/net/dsa/mt7530.c | 6 +++++-
  14  1 file changed, 5 insertions(+), 1 deletion(-)
  15
  16 --- a/drivers/net/dsa/mt7530.c
  17 +++ b/drivers/net/dsa/mt7530.c
  18 @@ -2422,7 +2422,7 @@ mt7531_setup(struct dsa_switch *ds)
  19         struct mt7530_priv *priv = ds->priv;
  20         struct mt7530_dummy_poll p;
  21         u32 val, id;
  22 -       int ret;
  23 +       int ret, i;
  24
  25         /* Reset whole chip through gpio pin or memory-mapped registers for
  26          * different type of hardware
  27 @@ -2454,6 +2454,10 @@ mt7531_setup(struct dsa_switch *ds)
  28                 return -ENODEV;
  29         }
  30
  31 +       /* all MACs must be forced link-down before sw reset */
  32 +       for (i = 0; i < MT7530_NUM_PORTS; i++)
  33 +               mt7530_write(priv, MT7530_PMCR_P(i), MT7531_FORCE_LNK);
  34 +
  35         /* Reset the switch through internal reset */
  36         mt7530_write(priv, MT7530_SYS_CTRL,
  37                      SYS_CTRL_PHY_RST | SYS_CTRL_SW_RST |