target/linux/generic/backport-5.10/792-v5.15-0002-net-dsa-b53-Set-correct-number-of-ports-in-the-DSA-s.patch

   1 From d12e1c4649883e8ca5e8ff341e1948b3b6313259 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Thu, 2 Sep 2021 10:30:51 +0200
   4 Subject: [PATCH] net: dsa: b53: Set correct number of ports in the DSA struct
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Setting DSA_MAX_PORTS caused DSA to call b53 callbacks (e.g.
  10 b53_disable_port() during dsa_register_switch()) for invalid
  11 (non-existent) ports. That made b53 modify unrelated registers and is
  12 one of reasons for a broken BCM5301x support.
  13
  14 This problem exists for years but DSA_MAX_PORTS usage has changed few
  15 times. It seems the most accurate to reference commit dropping
  16 dsa_switch_alloc() in the Fixes tag.
  17
  18 Fixes: 7e99e3470172 ("net: dsa: remove dsa_switch_alloc helper")
  19 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  20 Signed-off-by: David S. Miller <davem@davemloft.net>
  21 ---
  22  drivers/net/dsa/b53/b53_common.c | 3 ++-
  23  1 file changed, 2 insertions(+), 1 deletion(-)
  24
  25 --- a/drivers/net/dsa/b53/b53_common.c
  26 +++ b/drivers/net/dsa/b53/b53_common.c
  27 @@ -2587,6 +2587,8 @@ static int b53_switch_init(struct b53_de
  28         dev->enabled_ports |= BIT(dev->cpu_port);
  29         dev->num_ports = fls(dev->enabled_ports);
  30
  31 +       dev->ds->num_ports = min_t(unsigned int, dev->num_ports, DSA_MAX_PORTS);
  32 +
  33         /* Include non standard CPU port built-in PHYs to be probed */
  34         if (is539x(dev) || is531x5(dev)) {
  35                 for (i = 0; i < dev->num_ports; i++) {
  36 @@ -2631,7 +2633,6 @@ struct b53_device *b53_switch_alloc(stru
  37                 return NULL;
  38
  39         ds->dev = base;
  40 -       ds->num_ports = DSA_MAX_PORTS;
  41
  42         dev = devm_kzalloc(base, sizeof(*dev), GFP_KERNEL);
  43         if (!dev)