Re: [RFC PATCH 4/5] net: macb: Add support for suspend/resume with full power down

From: Claudiu Beznea
Date: Thu May 03 2018 - 06:09:56 EST




On 22.03.2018 15:51, harinikatakamlinux@xxxxxxxxx wrote:
> From: Harini Katakam <harinik@xxxxxxxxxx>
>
> When macb device is suspended and system is powered down, the clocks
> are removed and hence macb should be closed gracefully and restored
> upon resume.

Is this a power saving mode which shut down the core?

This patch does the same by switching off the net device,
> suspending phy and performing necessary cleanup of interrupts and BDs.
> Upon resume, all these are reinitialized again.
>
> Reset of macb device is done only when GEM is not a wake device.
> Even when gem is a wake device, tx queues can be stopped and ptp device
> can be closed (tsu clock will be disabled in pm_runtime_suspend) as
> wake event detection has no dependency on this.
>
> Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx>
> Signed-off-by: Harini Katakam <harinik@xxxxxxxxxx>
> ---
> drivers/net/ethernet/cadence/macb_main.c | 38 ++++++++++++++++++++++++++++++--
> 1 file changed, 36 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index ce75088..bca91bd 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -4167,16 +4167,33 @@ static int __maybe_unused macb_suspend(struct device *dev)
> struct platform_device *pdev = to_platform_device(dev);
> struct net_device *netdev = platform_get_drvdata(pdev);
> struct macb *bp = netdev_priv(netdev);
> + struct macb_queue *queue = bp->queues;
> + unsigned long flags;
> + unsigned int q;
> +
> + if (!netif_running(netdev))
> + return 0;
>
> - netif_carrier_off(netdev);
> - netif_device_detach(netdev);
>
> if (bp->wol & MACB_WOL_ENABLED) {
> macb_writel(bp, IER, MACB_BIT(WOL));
> macb_writel(bp, WOL, MACB_BIT(MAG));
> enable_irq_wake(bp->queues[0].irq);
> + netif_device_detach(netdev);
> + } else {
> + netif_device_detach(netdev);
> + for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue)
> + napi_disable(&queue->napi);
> + phy_stop(netdev->phydev);
> + phy_suspend(netdev->phydev);
> + spin_lock_irqsave(&bp->lock, flags);
> + macb_reset_hw(bp);
> + spin_unlock_irqrestore(&bp->lock, flags);

Wouldn't be simple to just call macb_close() here?

> }
>
> + netif_carrier_off(netdev);
> + if (bp->ptp_info)
> + bp->ptp_info->ptp_remove(netdev);
> pm_runtime_force_suspend(dev);
>
> return 0;
> @@ -4187,6 +4204,11 @@ static int __maybe_unused macb_resume(struct device *dev)
> struct platform_device *pdev = to_platform_device(dev);
> struct net_device *netdev = platform_get_drvdata(pdev);
> struct macb *bp = netdev_priv(netdev);
> + struct macb_queue *queue = bp->queues;
> + unsigned int q;
> +
> + if (!netif_running(netdev))
> + return 0;
>
> pm_runtime_force_resume(dev);
>
> @@ -4194,9 +4216,21 @@ static int __maybe_unused macb_resume(struct device *dev)
> macb_writel(bp, IDR, MACB_BIT(WOL));
> macb_writel(bp, WOL, 0);
> disable_irq_wake(bp->queues[0].irq);
> + } else {
> + macb_writel(bp, NCR, MACB_BIT(MPE));
> + for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue)
> + napi_enable(&queue->napi);
> + netif_carrier_on(netdev);
> + phy_resume(netdev->phydev);
> + phy_start(netdev->phydev);
> }
>
> + bp->macbgem_ops.mog_init_rings(bp);
> + macb_init_hw(bp);
> + macb_set_rx_mode(netdev);
> netif_device_attach(netdev);
> + if (bp->ptp_info)
> + bp->ptp_info->ptp_init(netdev);

Wouln't be simpler to call macb_open() here?

>
> return 0;
> }
>