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

Maciej Fijalkowski
2022-11-25T15:07:46Z

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;

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->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
>