Re: [RFC PATCH net-next v2 01/10] net: dsa: b53: add support for FDB operations on 5325/5365

El mié, 4 jun 2025 a las 8:32, Jonas Gorski ([off-list ref]) escribió:

On Wed, Jun 4, 2025 at 12:10 AM Florian Fainelli
[off-list ref] wrote:

quoted

On 6/3/25 13:48, Álvaro Fernández Rojas wrote:

quoted

From: Florian Fainelli <f.fainelli@gmail.com>

BCM5325 and BCM5365 are part of a much older generation of switches which,
due to their limited number of ports and VLAN entries (up to 256) allowed
a single 64-bit register to hold a full ARL entry.
This requires a little bit of massaging when reading, writing and
converting ARL entries in both directions.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <redacted>
---

[snip]

quoted

  static int b53_arl_op(struct b53_device *dev, int op, int port,
                    const unsigned char *addr, u16 vid, bool is_valid)
  {

@@ -1795,14 +1834,18 @@ static int b53_arl_op(struct b53_device *dev, int op, int port,

      /* Perform a read for the given MAC and VID */
      b53_write48(dev, B53_ARLIO_PAGE, B53_MAC_ADDR_IDX, mac);
-     b53_write16(dev, B53_ARLIO_PAGE, B53_VLAN_ID_IDX, vid);
+     if (!is5325(dev))
+             b53_write16(dev, B53_ARLIO_PAGE, B53_VLAN_ID_IDX, vid);

I used the 5325M-DS113-RDS datasheet for this code initially but the
5325E-DS14-R datasheet shows that this register is defined. It's not
clear to me how to differentiate the two kinds of switches. The 5325M
would report itself as:

0x00406330

in the integrated PHY PHYSID1/2 registers, whereas a 5325E would report
itself as 0x0143bc30. Maybe we can use that to key off the very first
generation 5325 switches?

According to the product brief and other documents BCM5325M does not
support 802.1Q VLANs, which would explain the missing register
descriptions. It does have 2k ARL entries compared to 1k for the 5325E
though, so I now see where that value comes from.

If it really doesn't support 802.1Q, then checking if related
registers are writable might also work.

Considering that I don't have access to a 5325M in order to properly
test it, I prefer the solution proposed by Florian.

I've implemented it in the following branch:
https://github.com/Noltari/linux/commits/b53-bcm5325-v3/
https://github.com/Noltari/linux/commit/e2d3d541ac421bbb5d2fc783e07fda26b105d1a5

I will wait a bit just in case there are some comments for the
recently submitted v2 of the dsa tag patches and then I will merge
both sets of patches into one since your proposed change of checking
the tag protocol for the BRCM_HDR register access requires having the
new legacy FCS tag.

Jonas

Best regards,
Álvaro.