[[PATCH,net]] net: dsa: mt7530: Change the LINK bit to reflect the link status

[[PATCH,net]] net: dsa: mt7530: Change the LINK bit to reflect the link status

[René van Dorst]

Andrew reported:

After a number of network port link up/down changes, sometimes the switch
port gets stuck in a state where it thinks it is still transmitting packets
but the cpu port is not actually transmitting anymore. In this state you
will see a message on the console
"mtk_soc_eth 1e100000.ethernet eth0: transmit timed out" and the Tx counter
in ifconfig will be incrementing on virtual port, but not incrementing on
cpu port.

The issue is that MAC TX/RX status has no impact on the link status or
queue manager of the switch. So the queue manager just queues up packets
of a disabled port and sends out pause frames when the queue is full.

Change the LINK bit to reflect the link status.

Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
Reported-by: Andrew Smith <andrew.smith@digi.com>
Signed-off-by: René van Dorst <opensource@vdorst.com>
---
 drivers/net/dsa/mt7530.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 9ee3f263d529..d422d3d6a129 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -566,7 +566,7 @@ mt7530_mib_reset(struct dsa_switch *ds)
 static void
 mt7530_port_set_status(struct mt7530_priv *priv, int port, int enable)
 {
-	u32 mask = PMCR_TX_EN | PMCR_RX_EN;
+	u32 mask = PMCR_TX_EN | PMCR_RX_EN | PMCR_FORCE_LNK;
 
 	if (enable)
 		mt7530_set(priv, MT7530_PMCR_P(port), mask);
@@ -1512,7 +1512,7 @@ static void mt7530_phylink_mac_config(struct dsa_switch *ds, int port,
 	mcr_new &= ~(PMCR_FORCE_SPEED_1000 | PMCR_FORCE_SPEED_100 |
 		     PMCR_FORCE_FDX | PMCR_TX_FC_EN | PMCR_RX_FC_EN);
 	mcr_new |= PMCR_IFG_XMIT(1) | PMCR_MAC_MODE | PMCR_BACKOFF_EN |
-		   PMCR_BACKPR_EN | PMCR_FORCE_MODE | PMCR_FORCE_LNK;
+		   PMCR_BACKPR_EN | PMCR_FORCE_MODE;
 
 	/* Are we connected to external phy */
 	if (port == 5 && dsa_is_user_port(ds, 5))
-- 
2.25.1

Re: [[PATCH,net]] net: dsa: mt7530: Change the LINK bit to reflect the link status

[Vivien Didelot]

Hi René,

On Thu, 19 Mar 2020 14:47:56 +0100, René van Dorst <opensource@vdorst.com> wrote:
> Andrew reported:
> 
> After a number of network port link up/down changes, sometimes the switch
> port gets stuck in a state where it thinks it is still transmitting packets
> but the cpu port is not actually transmitting anymore. In this state you
> will see a message on the console
> "mtk_soc_eth 1e100000.ethernet eth0: transmit timed out" and the Tx counter
> in ifconfig will be incrementing on virtual port, but not incrementing on
> cpu port.
> 
> The issue is that MAC TX/RX status has no impact on the link status or
> queue manager of the switch. So the queue manager just queues up packets
> of a disabled port and sends out pause frames when the queue is full.
> 
> Change the LINK bit to reflect the link status.
> 
> Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
> Reported-by: Andrew Smith <andrew.smith@digi.com>
> Signed-off-by: René van Dorst <opensource@vdorst.com>

Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>

For the subject prefix, it is preferable to use "[PATCH net]" over
"[[PATCH,net]]". You can easily add this bracketed prefix with git
format-patch's option --subject-prefix="PATCH net".


Thank you,

	Vivien

Re: [[PATCH,net]] net: dsa: mt7530: Change the LINK bit to reflect the link status

[Florian Fainelli]

Le 2020-03-19 à 06:47, René van Dorst a écrit :
> Andrew reported:
> 
> After a number of network port link up/down changes, sometimes the switch
> port gets stuck in a state where it thinks it is still transmitting packets
> but the cpu port is not actually transmitting anymore. In this state you
> will see a message on the console
> "mtk_soc_eth 1e100000.ethernet eth0: transmit timed out" and the Tx counter
> in ifconfig will be incrementing on virtual port, but not incrementing on
> cpu port.
> 
> The issue is that MAC TX/RX status has no impact on the link status or
> queue manager of the switch. So the queue manager just queues up packets
> of a disabled port and sends out pause frames when the queue is full.
> 
> Change the LINK bit to reflect the link status.
> 
> Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
> Reported-by: Andrew Smith <andrew.smith@digi.com>
> Signed-off-by: René van Dorst <opensource@vdorst.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [[PATCH,net]] net: dsa: mt7530: Change the LINK bit to reflect the link status

[René van Dorst]

Quoting Vivien Didelot <vivien.didelot@gmail.com>:

> Hi René,
>
> On Thu, 19 Mar 2020 14:47:56 +0100, René van Dorst  
> <opensource@vdorst.com> wrote:
>> Andrew reported:
>>
>> After a number of network port link up/down changes, sometimes the switch
>> port gets stuck in a state where it thinks it is still transmitting packets
>> but the cpu port is not actually transmitting anymore. In this state you
>> will see a message on the console
>> "mtk_soc_eth 1e100000.ethernet eth0: transmit timed out" and the Tx counter
>> in ifconfig will be incrementing on virtual port, but not incrementing on
>> cpu port.
>>
>> The issue is that MAC TX/RX status has no impact on the link status or
>> queue manager of the switch. So the queue manager just queues up packets
>> of a disabled port and sends out pause frames when the queue is full.
>>
>> Change the LINK bit to reflect the link status.
>>
>> Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek  
>> MT7530 switch")
>> Reported-by: Andrew Smith <andrew.smith@digi.com>
>> Signed-off-by: René van Dorst <opensource@vdorst.com>
>

Hi Vivien,

> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
>
> For the subject prefix, it is preferable to use "[PATCH net]" over
> "[[PATCH,net]]". You can easily add this bracketed prefix with git
> format-patch's option --subject-prefix="PATCH net".

Thanks for reviewing.

Funny is that I used subject-prefix option but I with the brackets.
Like --subject-prefix="[PATCH,net]" but not realizing that git also
add brackets. I didn't noticed until I got an email back from the
mailinglist that it had double brackets.
Next time I use "[PATCH net]".

Great,

René


>
>
> Thank you,
>
> 	Vivien

Re: [[PATCH,net]] net: dsa: mt7530: Change the LINK bit to reflect the link status

[David Miller]

From: René van Dorst <opensource@vdorst.com>
Date: Thu, 19 Mar 2020 14:47:56 +0100

> Andrew reported:
> 
> After a number of network port link up/down changes, sometimes the switch
> port gets stuck in a state where it thinks it is still transmitting packets
> but the cpu port is not actually transmitting anymore. In this state you
> will see a message on the console
> "mtk_soc_eth 1e100000.ethernet eth0: transmit timed out" and the Tx counter
> in ifconfig will be incrementing on virtual port, but not incrementing on
> cpu port.
> 
> The issue is that MAC TX/RX status has no impact on the link status or
> queue manager of the switch. So the queue manager just queues up packets
> of a disabled port and sends out pause frames when the queue is full.
> 
> Change the LINK bit to reflect the link status.
> 
> Fixes: b8f126a8d543 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
> Reported-by: Andrew Smith <andrew.smith@digi.com>
> Signed-off-by: René van Dorst <opensource@vdorst.com>

Applied and queued up for -stable, thanks.