[net] net: dsa: qca8k: Use up to 7 ports for all operations

The QCA8K family supports up to 7 ports. So use the existing
QCA8K_NUM_PORTS define to allocate the switch structure and limit all
operations with the switch ports.

This was not an issue until commit 0394a63acfe2 ("net: dsa: enable and
disable all ports") disabled all unused ports. Since the unused ports 7-11
are outside of the correct register range on this switch some registers
were rewritten with invalid content.

Fixes: 6b93fb46480a ("net-next: dsa: add new driver for qca8xxx family")
Fixes: a0c02161ecfc ("net: dsa: variable number of ports")
Fixes: 0394a63acfe2 ("net: dsa: enable and disable all ports")
Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
---
I am not sure which of the fixes tags should be used but this definetelly
fixes something..

IMHO the 0394a63acfe2 ("net: dsa: enable and disable all ports") did not
cause the issue but made it visible.

 drivers/net/dsa/qca8k.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

On 26. 09. 19 10:59, Michal Vokáč wrote:
> The QCA8K family supports up to 7 ports. So use the existing
> QCA8K_NUM_PORTS define to allocate the switch structure and limit all
> operations with the switch ports.
> 
> This was not an issue until commit 0394a63acfe2 ("net: dsa: enable and
> disable all ports") disabled all unused ports. Since the unused ports 7-11
> are outside of the correct register range on this switch some registers
> were rewritten with invalid content.
> 
> Fixes: 6b93fb46480a ("net-next: dsa: add new driver for qca8xxx family")
> Fixes: a0c02161ecfc ("net: dsa: variable number of ports")
> Fixes: 0394a63acfe2 ("net: dsa: enable and disable all ports")
> Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>

More recent patches on the list are getting attention.
Is this one falling through the cracks?

> ---
> I am not sure which of the fixes tags should be used but this definetelly
> fixes something..
> 
> IMHO the 0394a63acfe2 ("net: dsa: enable and disable all ports") did not
> cause the issue but made it visible.
> 
>   drivers/net/dsa/qca8k.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
> index 16f15c93a102..bbeeb8618c80 100644
> --- a/drivers/net/dsa/qca8k.c
> +++ b/drivers/net/dsa/qca8k.c
> @@ -705,7 +705,7 @@ qca8k_setup(struct dsa_switch *ds)
>   		    BIT(0) << QCA8K_GLOBAL_FW_CTRL1_UC_DP_S);
>   
>   	/* Setup connection between CPU port & user ports */
> -	for (i = 0; i < DSA_MAX_PORTS; i++) {
> +	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
>   		/* CPU port gets connected to all user ports of the switch */
>   		if (dsa_is_cpu_port(ds, i)) {
>   			qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(QCA8K_CPU_PORT),
> @@ -1074,7 +1074,7 @@ qca8k_sw_probe(struct mdio_device *mdiodev)
>   	if (id != QCA8K_ID_QCA8337)
>   		return -ENODEV;
>   
> -	priv->ds = dsa_switch_alloc(&mdiodev->dev, DSA_MAX_PORTS);
> +	priv->ds = dsa_switch_alloc(&mdiodev->dev, QCA8K_NUM_PORTS);
>   	if (!priv->ds)
>   		return -ENOMEM;
>   
>

On Mon, Sep 30, 2019 at 03:34:31PM +0200, Michal Vokáč wrote:
> On 26. 09. 19 10:59, Michal Vokáč wrote:
> > The QCA8K family supports up to 7 ports. So use the existing
> > QCA8K_NUM_PORTS define to allocate the switch structure and limit all
> > operations with the switch ports.
> > 
> > This was not an issue until commit 0394a63acfe2 ("net: dsa: enable and
> > disable all ports") disabled all unused ports. Since the unused ports 7-11
> > are outside of the correct register range on this switch some registers
> > were rewritten with invalid content.
> > 
> > Fixes: 6b93fb46480a ("net-next: dsa: add new driver for qca8xxx family")
> > Fixes: a0c02161ecfc ("net: dsa: variable number of ports")
> > Fixes: 0394a63acfe2 ("net: dsa: enable and disable all ports")
> > Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
> 
> More recent patches on the list are getting attention.
> Is this one falling through the cracks?

Probably not, it is missing a review-by, from somebody David trusts.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

From: Michal Vokáč <michal.vokac@ysoft.com>
Date: Thu, 26 Sep 2019 10:59:17 +0200

> The QCA8K family supports up to 7 ports. So use the existing
> QCA8K_NUM_PORTS define to allocate the switch structure and limit all
> operations with the switch ports.
> 
> This was not an issue until commit 0394a63acfe2 ("net: dsa: enable and
> disable all ports") disabled all unused ports. Since the unused ports 7-11
> are outside of the correct register range on this switch some registers
> were rewritten with invalid content.
> 
> Fixes: 6b93fb46480a ("net-next: dsa: add new driver for qca8xxx family")
> Fixes: a0c02161ecfc ("net: dsa: variable number of ports")
> Fixes: 0394a63acfe2 ("net: dsa: enable and disable all ports")
> Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>

Applied.