Messages in this thread Patch in this message | | | Subject | Re: [PATCH 13/13] net: ravb: Add runtime PM support | From | Sergey Shtylyov <> | Date | Wed, 22 Nov 2023 19:25:48 +0300 |
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On 11/20/23 11:46 AM, Claudiu wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> RZ/G3S supports enabling/disabling clocks for its modules (including > Ethernet module). For this commit adds runtime PM support which > relies on PM domain to enable/disable Ethernet clocks.
That's not exactly something new in RZ/G3S. The ravb driver has unconditional RPM calls already in the probe() and remove() methods... And the sh_eth driver has RPM support since 2009...
> At the end of probe ravb_pm_runtime_put() is called which will turn
I'd suggest a shorter name, like ravb_rpm_put() but (looking at this function) it doesn't seem hardly needed...
> off the Ethernet clocks (if no other request arrives at the driver). > After that if the interface is brought up (though ravb_open()) then > the clocks remain enabled until interface is brought down (operation > done though ravb_close()). > > If any request arrives to the driver while the interface is down the > clocks are enabled to serve the request and then disabled. > > Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> > --- > drivers/net/ethernet/renesas/ravb.h | 1 + > drivers/net/ethernet/renesas/ravb_main.c | 99 ++++++++++++++++++++++-- > 2 files changed, 93 insertions(+), 7 deletions(-) > > diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h > index c2d8d890031f..50f358472aab 100644 > --- a/drivers/net/ethernet/renesas/ravb.h > +++ b/drivers/net/ethernet/renesas/ravb.h > @@ -1044,6 +1044,7 @@ struct ravb_hw_info { > unsigned magic_pkt:1; /* E-MAC supports magic packet detection */ > unsigned half_duplex:1; /* E-MAC supports half duplex mode */ > unsigned refclk_in_pd:1; /* Reference clock is part of a power domain. */ > + unsigned rpm:1; /* Runtime PM available. */
No, I don't think this flag makes any sense. We should support RPM unconditionally...
[...] > diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c > index f4634ac0c972..d70ed7e5f7f6 100644 > --- a/drivers/net/ethernet/renesas/ravb_main.c > +++ b/drivers/net/ethernet/renesas/ravb_main.c > @@ -145,12 +145,41 @@ static void ravb_read_mac_address(struct device_node *np, [...] > +static void ravb_pm_runtime_put(struct ravb_private *priv) > +{ > + const struct ravb_hw_info *info = priv->info; > + struct device *dev = &priv->pdev->dev; > + > + if (!info->rpm) > + return; > + > + pm_runtime_mark_last_busy(dev);
Not very familiar with RPM... what's this for?
> + pm_runtime_put_autosuspend(dev);
Why not the usual pm_runtime_put()?
> +} > + > static void ravb_mdio_ctrl(struct mdiobb_ctrl *ctrl, u32 mask, int set) > { > struct ravb_private *priv = container_of(ctrl, struct ravb_private, > mdiobb); > + int ret; > + > + ret = ravb_pm_runtime_get(priv); > + if (ret < 0) > + return; > > ravb_modify(priv->ndev, PIR, mask, set ? mask : 0); > + > + ravb_pm_runtime_put(priv);
Hmm, does this even work? :-/ Do the MDIO bits retain the values while the AVB core is not clocked or even powered down? Note that the sh_eth driver has RPM calls in the {read|write}_c{22?45}() methods which do the full register read/write while the core is powere up and clocked...
[...] > @@ -2064,6 +2107,11 @@ static struct net_device_stats *ravb_get_stats(struct net_device *ndev) > struct ravb_private *priv = netdev_priv(ndev); > const struct ravb_hw_info *info = priv->info; > struct net_device_stats *nstats, *stats0, *stats1; > + int ret; > + > + ret = ravb_pm_runtime_get(priv); > + if (ret < 0) > + return NULL;
Hm, sh_eth.c doesn't have any RPM calls in this method. Again, do the hardware counters remain valid across powering the MAC core down?
[...] > @@ -2115,11 +2165,18 @@ static void ravb_set_rx_mode(struct net_device *ndev) > { > struct ravb_private *priv = netdev_priv(ndev); > unsigned long flags; > + int ret; > + > + ret = ravb_pm_runtime_get(priv); > + if (ret < 0) > + return;
Hm, sh_eth.c doesn't have any RPM calls in this method either. Does changing the promiscous mode have sense for an offlined interface?
[...] > @@ -2187,6 +2244,11 @@ static int ravb_close(struct net_device *ndev) > if (info->nc_queues) > ravb_ring_free(ndev, RAVB_NC); > > + /* Note that if RPM is enabled on plaforms with ccc_gac=1 this needs to be
It's "platforms". :-)
> skipped and
Overly long line?
> + * added to suspend function after PTP is stopped. I guess we'll have to do that because RPM is actually not RZ/G3 specific...
> + */ > + ravb_pm_runtime_put(priv); > + > return 0; > } > > @@ -2636,6 +2699,12 @@ static int ravb_probe(struct platform_device *pdev) > if (error) > return error; > > + info = of_device_get_match_data(&pdev->dev); > + > + if (info->rpm) { > + pm_runtime_set_autosuspend_delay(&pdev->dev, 100);
Why exactly 100 ms?
> + pm_runtime_use_autosuspend(&pdev->dev); > + }
Before calling pm_runtime_enable()?
> pm_runtime_enable(&pdev->dev); [...] > @@ -2880,6 +2950,8 @@ static int ravb_probe(struct platform_device *pdev) > pm_runtime_put(&pdev->dev); > pm_runtime_disable: > pm_runtime_disable(&pdev->dev); > + if (info->rpm) > + pm_runtime_dont_use_autosuspend(&pdev->dev);
After calling pm_runtime_disable()?
[...] > @@ -2908,6 +2985,8 @@ static void ravb_remove(struct platform_device *pdev) > priv->desc_bat_dma); > pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > + if (info->rpm) > + pm_runtime_dont_use_autosuspend(&pdev->dev);
After calling pm_runtime_disable()?
[...]
MBR, Sergey
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