Re: [PATCH net v4 1/7] net: dsa: mt7530: fix trapping frames with multiple CPU ports on MT7531
From: Arınç ÜNAL
Date: Wed Jun 14 2023 - 16:57:34 EST
On 14.06.2023 22:43, Vladimir Oltean wrote:
On Mon, Jun 12, 2023 at 10:59:39AM +0300, arinc9.unal@xxxxxxxxx wrote:
From: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
Every bit of the CPU port bitmap for MT7531 and the switch on the MT7988
SoC represents a CPU port to trap frames to. These switches trap frames
received from a user port to the CPU port that is affine to the user port
from which the frames are received.
Currently, only the bit that corresponds to the first found CPU port is set
on the bitmap. When multiple CPU ports are being used, the trapped frames
from the user ports not affine to the first CPU port will be dropped as the
other CPU port is not set on the bitmap. The switch on the MT7988 SoC is
not affected as there's only one port to be used as a CPU port.
To fix this, introduce the MT7531_CPU_PMAP macro to individually set the
bits of the CPU port bitmap. Set the CPU port bitmap for MT7531 and the
switch on the MT7988 SoC on mt753x_cpu_port_enable() which runs on a loop
for each CPU port.
Add a comment to explain frame trapping for these switches.
According to the document MT7531 Reference Manual for Development Board
v1.0, the MT7531_CPU_PMAP bits are unset after reset so no need to clear it
beforehand. Since there's currently no public document for the switch on
the MT7988 SoC, I assume this is also the case for this switch.
Fixes: c288575f7810 ("net: dsa: mt7530: Add the support of MT7531 switch")
Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
---
Would you agree that this is just preparatory work for change "net: dsa:
introduce preferred_default_local_cpu_port and use on MT7530" and not a
fix to an existing problem in the code base?
Makes sense. Pre-preferred_default_local_cpu_port patch, there isn't a
case where there's a user port affine to a CPU port that is not enabled
on the CPU port bitmap. So yeah, this is just preparatory work for "net:
dsa: introduce preferred_default_local_cpu_port and use on MT7530".
So how do I change the patch to reflect this?
Arınç