[v4] net: dsa: mt7530: fix multiple CPU ports, BPDU and LLDP handling

[PATCH net v4 4/7] net: dsa: mt7530: fix handling of BPDUs on MT7530 switch

Posted by arinc9.unal@gmail.com 1 year, 3 months ago

From: Arınç ÜNAL <arinc.unal@arinc9.com>

BPDUs are link-local frames, therefore they must be trapped to the CPU
port. Currently, the MT7530 switch treats BPDUs as regular multicast
frames, therefore flooding them to user ports. To fix this, set BPDUs to be
trapped to the CPU port.

BPDUs received from a user port will be trapped to the numerically smallest
CPU port which is affine to the DSA conduit interface that is up.

Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
---
 drivers/net/dsa/mt7530.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 2bde2fdb5fba..e4c169843f2e 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2259,6 +2259,10 @@ mt7530_setup(struct dsa_switch *ds)
 
 	priv->p6_interface = PHY_INTERFACE_MODE_NA;
 
+	/* Trap BPDUs to the CPU port */
+	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
+		   MT753X_BPDU_CPU_ONLY);
+
 	/* Enable and reset MIB counters */
 	mt7530_mib_reset(ds);
 
-- 
2.39.2

Re: [PATCH net v4 4/7] net: dsa: mt7530: fix handling of BPDUs on MT7530 switch

Posted by Vladimir Oltean 1 year, 3 months ago

On Mon, Jun 12, 2023 at 10:59:42AM +0300, arinc9.unal@gmail.com wrote:
> From: Arınç ÜNAL <arinc.unal@arinc9.com>
> 
> BPDUs are link-local frames, therefore they must be trapped to the CPU
> port. Currently, the MT7530 switch treats BPDUs as regular multicast
> frames, therefore flooding them to user ports. To fix this, set BPDUs to be
> trapped to the CPU port.
> 
> BPDUs received from a user port will be trapped to the numerically smallest
> CPU port which is affine to the DSA conduit interface that is up.
> 
> Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
> ---
>  drivers/net/dsa/mt7530.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> index 2bde2fdb5fba..e4c169843f2e 100644
> --- a/drivers/net/dsa/mt7530.c
> +++ b/drivers/net/dsa/mt7530.c
> @@ -2259,6 +2259,10 @@ mt7530_setup(struct dsa_switch *ds)
>  
>  	priv->p6_interface = PHY_INTERFACE_MODE_NA;
>  
> +	/* Trap BPDUs to the CPU port */
> +	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
> +		   MT753X_BPDU_CPU_ONLY);
> +
>  	/* Enable and reset MIB counters */
>  	mt7530_mib_reset(ds);
>  
> -- 
> 2.39.2
> 

Where have you seen the BPC register in the memory map of MT7530 or MT7621?

Re: [PATCH net v4 4/7] net: dsa: mt7530: fix handling of BPDUs on MT7530 switch

Posted by Arınç ÜNAL 1 year, 3 months ago

On 14.06.2023 23:50, Vladimir Oltean wrote:
> On Mon, Jun 12, 2023 at 10:59:42AM +0300, arinc9.unal@gmail.com wrote:
>> From: Arınç ÜNAL <arinc.unal@arinc9.com>
>>
>> BPDUs are link-local frames, therefore they must be trapped to the CPU
>> port. Currently, the MT7530 switch treats BPDUs as regular multicast
>> frames, therefore flooding them to user ports. To fix this, set BPDUs to be
>> trapped to the CPU port.
>>
>> BPDUs received from a user port will be trapped to the numerically smallest
>> CPU port which is affine to the DSA conduit interface that is up.
>>
>> Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
>> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
>> ---
>>   drivers/net/dsa/mt7530.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
>> index 2bde2fdb5fba..e4c169843f2e 100644
>> --- a/drivers/net/dsa/mt7530.c
>> +++ b/drivers/net/dsa/mt7530.c
>> @@ -2259,6 +2259,10 @@ mt7530_setup(struct dsa_switch *ds)
>>   
>>   	priv->p6_interface = PHY_INTERFACE_MODE_NA;
>>   
>> +	/* Trap BPDUs to the CPU port */
>> +	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
>> +		   MT753X_BPDU_CPU_ONLY);
>> +
>>   	/* Enable and reset MIB counters */
>>   	mt7530_mib_reset(ds);
>>   
>> -- 
>> 2.39.2
>>
> 
> Where have you seen the BPC register in the memory map of MT7530 or MT7621?

I did not somehow dump the memory map of the switch hardware and confirm 
the BPC register is there, if that's what you're asking.

However, I can confirm the register is there and identical across all 
MT7530 variants. I have tested the function of the register on the MCM 
MT7530 on the MT7621 SoC and the standalone MT7530. The register is also 
described on the document MT7620 Programming Guide v1.0, page 262.

Arınç

Re: [PATCH net v4 4/7] net: dsa: mt7530: fix handling of BPDUs on MT7530 switch

Posted by Vladimir Oltean 1 year, 3 months ago

On Thu, Jun 15, 2023 at 12:05:44AM +0300, Arınç ÜNAL wrote:
> On 14.06.2023 23:50, Vladimir Oltean wrote:
> > Where have you seen the BPC register in the memory map of MT7530 or MT7621?
> 
> I did not somehow dump the memory map of the switch hardware and confirm the
> BPC register is there, if that's what you're asking.

I mean to say that I looked at

MT7530 Giga Switch programming guide.pdf
MT7621 Giga Switch Programming Guide.pdf
MT7621_ProgrammingGuide_GSW_v01.pdf

and I did not find this register.

> However, I can confirm the register is there and identical across all MT7530
> variants. I have tested the function of the register on the MCM MT7530 on
> the MT7621 SoC and the standalone MT7530. The register is also described on
> the document MT7620 Programming Guide v1.0, page 262.

Interesting. I did not have that one. Hard to keep up.

Re: [PATCH net v4 4/7] net: dsa: mt7530: fix handling of BPDUs on MT7530 switch

Posted by Arınç ÜNAL 1 year, 3 months ago

On 15 June 2023 00:16:57 EEST, Vladimir Oltean <olteanv@gmail.com> wrote:
>On Thu, Jun 15, 2023 at 12:05:44AM +0300, Arınç ÜNAL wrote:
>> On 14.06.2023 23:50, Vladimir Oltean wrote:
>> > Where have you seen the BPC register in the memory map of MT7530 or MT7621?
>> 
>> I did not somehow dump the memory map of the switch hardware and confirm the
>> BPC register is there, if that's what you're asking.
>
>I mean to say that I looked at
>
>MT7530 Giga Switch programming guide.pdf
>MT7621 Giga Switch Programming Guide.pdf
>MT7621_ProgrammingGuide_GSW_v01.pdf
>
>and I did not find this register.
>
>> However, I can confirm the register is there and identical across all MT7530
>> variants. I have tested the function of the register on the MCM MT7530 on
>> the MT7621 SoC and the standalone MT7530. The register is also described on
>> the document MT7620 Programming Guide v1.0, page 262.
>
>Interesting. I did not have that one. Hard to keep up.

I know the pain. The MT7530 registers are scattered throughout these four documents. TRGMII stuff is on MT7530 Giga Switch programming guide.pdf, etc. Good thing MT7531 Reference Manual for Development Board v1.0 has it all for MT7531.

Arınç