Re: [PATCH net-next] net: dsa: qca8k: Initialize the switch with correct number of ports

From: Michal VokÃÄ
Date: Fri Oct 25 2019 - 06:50:18 EST


On 24. 10. 19 18:33, Florian Fainelli wrote:
On 10/24/19 7:12 AM, Andrew Lunn wrote:
On Thu, Oct 24, 2019 at 03:46:58PM +0200, Michal VokÃÄ wrote:
Since commit 0394a63acfe2 ("net: dsa: enable and disable all ports")
the dsa core disables all unused ports of a switch. In this case
disabling ports with numbers higher than QCA8K_NUM_PORTS causes that
some switch registers are overwritten with incorrect content.

Humm.

The same problem might exist in other drivers:

linux/drivers/net/dsa$ grep -r "ds->num_ports = DSA_MAX_PORTS"
qca8k.c: priv->ds->num_ports = DSA_MAX_PORTS;
b53/b53_common.c: ds->num_ports = DSA_MAX_PORTS;

Not for b53 because this later gets clamped with dev->num_ports in
b53_setup().

I quickly checked the code and I think there is still an issue
in the b53_enable_port and b53_disable_port functions which are
called from the dsa_port_setup().

mt7530.c: priv->ds->num_ports = DSA_MAX_PORTS;
microchip/ksz_common.c: ds->num_ports = DSA_MAX_PORTS;

At first glance it looks like mt7530 and microchip has the same problem.

dsa_loop.c: ds->num_ports = DSA_MAX_PORTS;

dsa_loop.c looks O.K, it does support DSA_MAX_PORTS ports.

But the others?

Andrew

I can respin and fix those drivers as well. Or a separate patch
for each one?

Michal