Re: [PATCH v3 net-next 5/6] net: ethernet: ti: am65-cpsw: retain PORT_VLAN_REG after suspend/resume

[Roger Quadros <rogerq@kernel.org>]

On 25/11/2022 15:21, Maciej Fijalkowski wrote:
> On Wed, Nov 23, 2022 at 02:48:34PM +0200, Roger Quadros wrote:
>> During suspend resume the context of PORT_VLAN_REG is lost so
>> save it during suspend and restore it during resume for
>> host port and slave ports.
>>
>> Signed-off-by: Roger Quadros <rogerq@kernel.org>
>> Signed-off-by: David S. Miller <davem@davemloft.net>
>> ---
>>  drivers/net/ethernet/ti/am65-cpsw-nuss.c | 7 +++++++
>>  drivers/net/ethernet/ti/am65-cpsw-nuss.h | 4 ++++
>>  2 files changed, 11 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
>> index 0b59088e3728..f5357afde527 100644
>> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
>> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
>> @@ -2875,7 +2875,9 @@ static int am65_cpsw_nuss_suspend(struct device *dev)
>>  	struct am65_cpsw_port *port;
>>  	struct net_device *ndev;
>>  	int i, ret;
>> +	struct am65_cpsw_host *host_p = am65_common_get_host(common);
> 
> Nit: I see that retrieving host pointer depends on getting the common
> pointer first from dev_get_drvdata(dev) so pure RCT is not possible to
> maintain here but nonetheless I would move this line just below the common
> pointer:
> 
> 	struct am65_cpsw_common *common = dev_get_drvdata(dev);
> 	struct am65_cpsw_host *host = am65_common_get_host(common);
> 	struct am65_cpsw_port *port;
> 	struct net_device *ndev;
> 	int i, ret;

OK.

> 
> Also I think plain 'host' for variable name is just fine, no need for _p
> suffix to indicate it is a pointer. in that case you should go with
> common_p etc.

host_p is the naming convention used throughout the driver.
Do think it is a good idea to change it at this one place?

> 
>>  
>> +	host_p->vid_context = readl(host_p->port_base + AM65_CPSW_PORT_VLAN_REG_OFFSET);
>>  	for (i = 0; i < common->port_num; i++) {
>>  		port = &common->ports[i];
>>  		ndev = port->ndev;
>> @@ -2883,6 +2885,7 @@ static int am65_cpsw_nuss_suspend(struct device *dev)
>>  		if (!ndev)
>>  			continue;
>>  
>> +		port->vid_context = readl(port->port_base + AM65_CPSW_PORT_VLAN_REG_OFFSET);
>>  		netif_device_detach(ndev);
>>  		if (netif_running(ndev)) {
>>  			rtnl_lock();
>> @@ -2909,6 +2912,7 @@ static int am65_cpsw_nuss_resume(struct device *dev)
>>  	struct am65_cpsw_port *port;
>>  	struct net_device *ndev;
>>  	int i, ret;
>> +	struct am65_cpsw_host *host_p = am65_common_get_host(common);
>>  
>>  	ret = am65_cpsw_nuss_init_tx_chns(common);
>>  	if (ret)
>> @@ -2941,8 +2945,11 @@ static int am65_cpsw_nuss_resume(struct device *dev)
>>  		}
>>  
>>  		netif_device_attach(ndev);
>> +		writel(port->vid_context, port->port_base + AM65_CPSW_PORT_VLAN_REG_OFFSET);
>>  	}
>>  
>> +	writel(host_p->vid_context, host_p->port_base + AM65_CPSW_PORT_VLAN_REG_OFFSET);
>> +
>>  	return 0;
>>  }
>>  #endif /* CONFIG_PM_SLEEP */
>> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.h b/drivers/net/ethernet/ti/am65-cpsw-nuss.h
>> index 2c9850fdfcb6..e95cc37a7286 100644
>> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.h
>> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.h
>> @@ -55,12 +55,16 @@ struct am65_cpsw_port {
>>  	bool				rx_ts_enabled;
>>  	struct am65_cpsw_qos		qos;
>>  	struct devlink_port		devlink_port;
>> +	/* Only for suspend resume context */
>> +	u32				vid_context;
>>  };
>>  
>>  struct am65_cpsw_host {
>>  	struct am65_cpsw_common		*common;
>>  	void __iomem			*port_base;
>>  	void __iomem			*stat_base;
>> +	/* Only for suspend resume context */
>> +	u32				vid_context;
>>  };
>>  
>>  struct am65_cpsw_tx_chn {
>> -- 
>> 2.17.1
>>

--
cheers,
-roger