diff mbox series

[net-next] rswitch: Add PM ops

Message ID 20231012121618.267315-1-yoshihiro.shimoda.uh@renesas.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [net-next] rswitch: Add PM ops | expand

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Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1361 this patch: 1361
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 1386 this patch: 1386
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1386 this patch: 1386
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 66 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Yoshihiro Shimoda Oct. 12, 2023, 12:16 p.m. UTC
Add PM ops for Suspend to Idle. When the system suspended,
the Ethernet Serdes's clock will be stopped. So, this driver needs
to re-initialize the Ethernet Serdes by phy_init() in
renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 This patch is based on the latest net-next.git / next branch.
 After applied this patch with the following patches, the system can
 enter/exit Suspend to Idle without any error:

https://lore.kernel.org/netdev/20230201131454.1928136-1-yoshihiro.shimoda.uh@renesas.com/
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=510b18cf23b9bd8a982ef7f1fb19f3968a2bf787
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=053f13f67be6d02781730c9ac71abde6e9140610

 drivers/net/ethernet/renesas/rswitch.c | 43 ++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

Comments

Geert Uytterhoeven Oct. 12, 2023, 12:35 p.m. UTC | #1
Hi Shimoda-san,

On Thu, Oct 12, 2023 at 2:16 PM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com> wrote:
> Add PM ops for Suspend to Idle. When the system suspended,
> the Ethernet Serdes's clock will be stopped. So, this driver needs
> to re-initialize the Ethernet Serdes by phy_init() in
> renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Thanks for your patch!

> --- a/drivers/net/ethernet/renesas/rswitch.c
> +++ b/drivers/net/ethernet/renesas/rswitch.c
> @@ -17,6 +17,7 @@
>  #include <linux/of_net.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/rtnetlink.h>
>  #include <linux/slab.h>
> @@ -1315,6 +1316,7 @@ static int rswitch_phy_device_init(struct rswitch_device *rdev)
>         if (!phydev)
>                 goto out;
>         __set_bit(rdev->etha->phy_interface, phydev->host_interfaces);
> +       phydev->mac_managed_pm = true;
>
>         phydev = of_phy_connect(rdev->ndev, phy, rswitch_adjust_link, 0,
>                                 rdev->etha->phy_interface);
> @@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
>         platform_set_drvdata(pdev, NULL);
>  }
>
> +static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
> +{
> +       struct rswitch_private *priv = dev_get_drvdata(dev);
> +       struct net_device *ndev;
> +       int i;

unsigned int (also below)

> +
> +       rswitch_for_each_enabled_port(priv, i) {
> +               ndev = priv->rdev[i]->ndev;
> +               if (netif_running(ndev)) {
> +                       netif_device_detach(ndev);
> +                       rswitch_stop(ndev);
> +               }
> +               if (priv->rdev[i]->serdes->init_count)
> +                       phy_exit(priv->rdev[i]->serdes);

If !init_count, the PHY was not initialized before suspending? ...

> +       }
> +
> +       return 0;
> +}
> +
> +static int __maybe_unused renesas_eth_sw_resume(struct device *dev)
> +{
> +       struct rswitch_private *priv = dev_get_drvdata(dev);
> +       struct net_device *ndev;
> +       int i;
> +
> +       rswitch_for_each_enabled_port(priv, i) {
> +               phy_init(priv->rdev[i]->serdes);

... while it is always initialized after resuming? Is that intentional,
or should the pre-suspend state be preserved?

> +               ndev = priv->rdev[i]->ndev;
> +               if (netif_running(ndev)) {
> +                       rswitch_open(ndev);
> +                       netif_device_attach(ndev);
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(renesas_eth_sw_pm_ops, renesas_eth_sw_suspend,
> +                        renesas_eth_sw_resume);

Please use DEFINE_SIMPLE_DEV_PM_OPS() instead, so you can drop the
__maybe_unused tags from the callbacks.

> +
>  static struct platform_driver renesas_eth_sw_driver_platform = {
>         .probe = renesas_eth_sw_probe,
>         .remove_new = renesas_eth_sw_remove,
>         .driver = {
>                 .name = "renesas_eth_sw",
> +               .pm = &renesas_eth_sw_pm_ops,

pm_sleep_ptr(...)

>                 .of_match_table = renesas_eth_sw_of_table,
>         }
>  };

Gr{oetje,eeting}s,

                        Geert
Yoshihiro Shimoda Oct. 13, 2023, 2:10 a.m. UTC | #2
Hi Geert-san,

> From: Geert Uytterhoeven, Sent: Thursday, October 12, 2023 9:35 PM
> 
> Hi Shimoda-san,
> 
> On Thu, Oct 12, 2023 at 2:16 PM Yoshihiro Shimoda
> <yoshihiro.shimoda.uh@renesas.com> wrote:
> > Add PM ops for Suspend to Idle. When the system suspended,
> > the Ethernet Serdes's clock will be stopped. So, this driver needs
> > to re-initialize the Ethernet Serdes by phy_init() in
> > renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> 
> Thanks for your patch!

Thank you for your review!

> > --- a/drivers/net/ethernet/renesas/rswitch.c
> > +++ b/drivers/net/ethernet/renesas/rswitch.c
> > @@ -17,6 +17,7 @@
> >  #include <linux/of_net.h>
> >  #include <linux/phy/phy.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/pm.h>
> >  #include <linux/pm_runtime.h>
> >  #include <linux/rtnetlink.h>
> >  #include <linux/slab.h>
> > @@ -1315,6 +1316,7 @@ static int rswitch_phy_device_init(struct rswitch_device *rdev)
> >         if (!phydev)
> >                 goto out;
> >         __set_bit(rdev->etha->phy_interface, phydev->host_interfaces);
> > +       phydev->mac_managed_pm = true;
> >
> >         phydev = of_phy_connect(rdev->ndev, phy, rswitch_adjust_link, 0,
> >                                 rdev->etha->phy_interface);
> > @@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
> >         platform_set_drvdata(pdev, NULL);
> >  }
> >
> > +static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
> > +{
> > +       struct rswitch_private *priv = dev_get_drvdata(dev);
> > +       struct net_device *ndev;
> > +       int i;
> 
> unsigned int (also below)

I don't know why unsigned int is needed. Other functions use 
rswitch_for_each_enabled_port{_continue_reverse}() with int.
Especially, rswitch_for_each_enabled_port_continue_reverse()
has the following code, unsigned int will not work correctly:
---
#define rswitch_for_each_enabled_port_continue_reverse(priv, i) \
        for (i--; i >= 0; i--)                                  \
                if (priv->rdev[i]->disabled)                    \
                        continue;                               \
                else
---

So, I would like to keep this for consistency with other functions'
implementation. But, what do you think?

> > +
> > +       rswitch_for_each_enabled_port(priv, i) {
> > +               ndev = priv->rdev[i]->ndev;
> > +               if (netif_running(ndev)) {
> > +                       netif_device_detach(ndev);
> > +                       rswitch_stop(ndev);
> > +               }
> > +               if (priv->rdev[i]->serdes->init_count)
> > +                       phy_exit(priv->rdev[i]->serdes);
> 
> If !init_count, the PHY was not initialized before suspending? ...

Yes, it was possible if renesas_eth_sw_resume() called phy_init()
and it failed.

> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static int __maybe_unused renesas_eth_sw_resume(struct device *dev)
> > +{
> > +       struct rswitch_private *priv = dev_get_drvdata(dev);
> > +       struct net_device *ndev;
> > +       int i;
> > +
> > +       rswitch_for_each_enabled_port(priv, i) {
> > +               phy_init(priv->rdev[i]->serdes);
> 
> ... while it is always initialized after resuming? Is that intentional,
> or should the pre-suspend state be preserved?

Yes, that is intentional. After this driver was probed, the phy was always
initialized.

> > +               ndev = priv->rdev[i]->ndev;
> > +               if (netif_running(ndev)) {
> > +                       rswitch_open(ndev);
> > +                       netif_device_attach(ndev);
> > +               }
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(renesas_eth_sw_pm_ops, renesas_eth_sw_suspend,
> > +                        renesas_eth_sw_resume);
> 
> Please use DEFINE_SIMPLE_DEV_PM_OPS() instead, so you can drop the
> __maybe_unused tags from the callbacks.

I got it. I'll fix them.

> > +
> >  static struct platform_driver renesas_eth_sw_driver_platform = {
> >         .probe = renesas_eth_sw_probe,
> >         .remove_new = renesas_eth_sw_remove,
> >         .driver = {
> >                 .name = "renesas_eth_sw",
> > +               .pm = &renesas_eth_sw_pm_ops,
> 
> pm_sleep_ptr(...)

I'll use it on v2.

Best regards,
Yoshihiro Shimoda

> >                 .of_match_table = renesas_eth_sw_of_table,
> >         }
> >  };
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
Geert Uytterhoeven Oct. 13, 2023, 7:28 a.m. UTC | #3
Hi Shimoda-san,

On Fri, Oct 13, 2023 at 4:10 AM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com> wrote:
> > From: Geert Uytterhoeven, Sent: Thursday, October 12, 2023 9:35 PM
> > On Thu, Oct 12, 2023 at 2:16 PM Yoshihiro Shimoda
> > <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > Add PM ops for Suspend to Idle. When the system suspended,
> > > the Ethernet Serdes's clock will be stopped. So, this driver needs
> > > to re-initialize the Ethernet Serdes by phy_init() in
> > > renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().
> > >
> > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> >
> > Thanks for your patch!
>
> Thank you for your review!
>
> > > --- a/drivers/net/ethernet/renesas/rswitch.c
> > > +++ b/drivers/net/ethernet/renesas/rswitch.c
> > > @@ -17,6 +17,7 @@
> > >  #include <linux/of_net.h>
> > >  #include <linux/phy/phy.h>
> > >  #include <linux/platform_device.h>
> > > +#include <linux/pm.h>
> > >  #include <linux/pm_runtime.h>
> > >  #include <linux/rtnetlink.h>
> > >  #include <linux/slab.h>
> > > @@ -1315,6 +1316,7 @@ static int rswitch_phy_device_init(struct rswitch_device *rdev)
> > >         if (!phydev)
> > >                 goto out;
> > >         __set_bit(rdev->etha->phy_interface, phydev->host_interfaces);
> > > +       phydev->mac_managed_pm = true;
> > >
> > >         phydev = of_phy_connect(rdev->ndev, phy, rswitch_adjust_link, 0,
> > >                                 rdev->etha->phy_interface);
> > > @@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
> > >         platform_set_drvdata(pdev, NULL);
> > >  }
> > >
> > > +static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
> > > +{
> > > +       struct rswitch_private *priv = dev_get_drvdata(dev);
> > > +       struct net_device *ndev;
> > > +       int i;
> >
> > unsigned int (also below)
>
> I don't know why unsigned int is needed. Other functions use

There's this old mantra "prefer unsigned over signed in C",
and a valid port array index here is always unsigned.

> rswitch_for_each_enabled_port{_continue_reverse}() with int.
> Especially, rswitch_for_each_enabled_port_continue_reverse()
> has the following code, unsigned int will not work correctly:

Oh, there is also a reverse variant, which indeed needs a signed
iterator, currently...

> ---
> #define rswitch_for_each_enabled_port_continue_reverse(priv, i) \
>         for (i--; i >= 0; i--)                                  \

I think this can be made to work with an unsigned iterator using

    for (; i-- > 0; )

>                 if (priv->rdev[i]->disabled)                    \
>                         continue;                               \
>                 else
> ---
>
> So, I would like to keep this for consistency with other functions'
> implementation. But, what do you think?

Consistency is good...
Surprising readers (why is this signed?) is bad...
It's hard to keep a good balance...

BTW, perhaps it would make sense to use the reverse order in suspend?
Although it probably doesn't matter, as rswitch_deinit() uses the
non-reverse order, too.

Gr{oetje,eeting}s,

                        Geert
Yoshihiro Shimoda Oct. 13, 2023, 8:55 a.m. UTC | #4
Hi Geert-san,

> From: Geert Uytterhoeven, Sent: Friday, October 13, 2023 4:29 PM
> 
> Hi Shimoda-san,
> 
> On Fri, Oct 13, 2023 at 4:10 AM Yoshihiro Shimoda
> <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > From: Geert Uytterhoeven, Sent: Thursday, October 12, 2023 9:35 PM
> > > On Thu, Oct 12, 2023 at 2:16 PM Yoshihiro Shimoda
> > > <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > > Add PM ops for Suspend to Idle. When the system suspended,
> > > > the Ethernet Serdes's clock will be stopped. So, this driver needs
> > > > to re-initialize the Ethernet Serdes by phy_init() in
> > > > renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().
> > > >
> > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > >
> > > Thanks for your patch!
> >
> > Thank you for your review!
> >
> > > > --- a/drivers/net/ethernet/renesas/rswitch.c
> > > > +++ b/drivers/net/ethernet/renesas/rswitch.c
> > > > @@ -17,6 +17,7 @@
> > > >  #include <linux/of_net.h>
> > > >  #include <linux/phy/phy.h>
> > > >  #include <linux/platform_device.h>
> > > > +#include <linux/pm.h>
> > > >  #include <linux/pm_runtime.h>
> > > >  #include <linux/rtnetlink.h>
> > > >  #include <linux/slab.h>
> > > > @@ -1315,6 +1316,7 @@ static int rswitch_phy_device_init(struct rswitch_device *rdev)
> > > >         if (!phydev)
> > > >                 goto out;
> > > >         __set_bit(rdev->etha->phy_interface, phydev->host_interfaces);
> > > > +       phydev->mac_managed_pm = true;
> > > >
> > > >         phydev = of_phy_connect(rdev->ndev, phy, rswitch_adjust_link, 0,
> > > >                                 rdev->etha->phy_interface);
> > > > @@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
> > > >         platform_set_drvdata(pdev, NULL);
> > > >  }
> > > >
> > > > +static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
> > > > +{
> > > > +       struct rswitch_private *priv = dev_get_drvdata(dev);
> > > > +       struct net_device *ndev;
> > > > +       int i;
> > >
> > > unsigned int (also below)
> >
> > I don't know why unsigned int is needed. Other functions use
> 
> There's this old mantra "prefer unsigned over signed in C",
> and a valid port array index here is always unsigned.

I understood it.

> > rswitch_for_each_enabled_port{_continue_reverse}() with int.
> > Especially, rswitch_for_each_enabled_port_continue_reverse()
> > has the following code, unsigned int will not work correctly:
> 
> Oh, there is also a reverse variant, which indeed needs a signed
> iterator, currently...
> 
> > ---
> > #define rswitch_for_each_enabled_port_continue_reverse(priv, i) \
> >         for (i--; i >= 0; i--)                                  \
> 
> I think this can be made to work with an unsigned iterator using
> 
>     for (; i-- > 0; )

I think that this loop cannot access index 0 :)

> >                 if (priv->rdev[i]->disabled)                    \
> >                         continue;                               \
> >                 else
> > ---
> >
> > So, I would like to keep this for consistency with other functions'
> > implementation. But, what do you think?
> 
> Consistency is good...
> Surprising readers (why is this signed?) is bad...
> It's hard to keep a good balance...
> 
> BTW, perhaps it would make sense to use the reverse order in suspend?
> Although it probably doesn't matter, as rswitch_deinit() uses the
> non-reverse order, too.

Thank you for your suggestion. I also think that we can use the
non-reverse order. So,
 1) Change "_reverse()" macro to others somehow.
 2) Change the type of i for "for_each" to unsigned int.
 3) Add PM ops.

Perhaps, can/should we merge the 1) and 2) to one patch?

Best regards,
Yoshihiro Shimoda

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
Geert Uytterhoeven Oct. 13, 2023, 9:19 a.m. UTC | #5
Hi Shimoda-san,

On Fri, Oct 13, 2023 at 10:55 AM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com> wrote:
> > From: Geert Uytterhoeven, Sent: Friday, October 13, 2023 4:29 PM
> > On Fri, Oct 13, 2023 at 4:10 AM Yoshihiro Shimoda
> > <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > > From: Geert Uytterhoeven, Sent: Thursday, October 12, 2023 9:35 PM
> > > > On Thu, Oct 12, 2023 at 2:16 PM Yoshihiro Shimoda
> > > > <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > > > Add PM ops for Suspend to Idle. When the system suspended,
> > > > > the Ethernet Serdes's clock will be stopped. So, this driver needs
> > > > > to re-initialize the Ethernet Serdes by phy_init() in
> > > > > renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().
> > > > >
> > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

> > > > > --- a/drivers/net/ethernet/renesas/rswitch.c
> > > > > +++ b/drivers/net/ethernet/renesas/rswitch.c
> > > > > @@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
> > > > >         platform_set_drvdata(pdev, NULL);
> > > > >  }
> > > > >
> > > > > +static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
> > > > > +{
> > > > > +       struct rswitch_private *priv = dev_get_drvdata(dev);
> > > > > +       struct net_device *ndev;
> > > > > +       int i;
> > > >
> > > > unsigned int (also below)
> > >
> > > I don't know why unsigned int is needed. Other functions use
> >
> > There's this old mantra "prefer unsigned over signed in C",
> > and a valid port array index here is always unsigned.
>
> I understood it.
>
> > > rswitch_for_each_enabled_port{_continue_reverse}() with int.
> > > Especially, rswitch_for_each_enabled_port_continue_reverse()
> > > has the following code, unsigned int will not work correctly:
> >
> > Oh, there is also a reverse variant, which indeed needs a signed
> > iterator, currently...
> >
> > > ---
> > > #define rswitch_for_each_enabled_port_continue_reverse(priv, i) \
> > >         for (i--; i >= 0; i--)                                  \
> >
> > I think this can be made to work with an unsigned iterator using
> >
> >     for (; i-- > 0; )
>
> I think that this loop cannot access index 0 :)

rswitch_for_each_enabled_port_continue_reverse() is meant to be
used in the error path, to tear down all ports that were initialized
succesfully? So i is always the index of the first port that failed to
initialize, i.e. i > 0 on entry.

See "git grep -Ww rswitch_for_each_enabled_port_continue_reverse".

Gr{oetje,eeting}s,

                        Geert
Yoshihiro Shimoda Oct. 13, 2023, 10:02 a.m. UTC | #6
Hi Geert-san,

> From: Geert Uytterhoeven, Sent: Friday, October 13, 2023 6:19 PM
> 
> Hi Shimoda-san,
> 
> On Fri, Oct 13, 2023 at 10:55 AM Yoshihiro Shimoda
> <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > From: Geert Uytterhoeven, Sent: Friday, October 13, 2023 4:29 PM
> > > On Fri, Oct 13, 2023 at 4:10 AM Yoshihiro Shimoda
> > > <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > > > From: Geert Uytterhoeven, Sent: Thursday, October 12, 2023 9:35 PM
> > > > > On Thu, Oct 12, 2023 at 2:16 PM Yoshihiro Shimoda
> > > > > <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > > > > Add PM ops for Suspend to Idle. When the system suspended,
> > > > > > the Ethernet Serdes's clock will be stopped. So, this driver needs
> > > > > > to re-initialize the Ethernet Serdes by phy_init() in
> > > > > > renesas_eth_sw_resume(). Otherwise, timeout happened in phy_power_on().
> > > > > >
> > > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> 
> > > > > > --- a/drivers/net/ethernet/renesas/rswitch.c
> > > > > > +++ b/drivers/net/ethernet/renesas/rswitch.c
> > > > > > @@ -1991,11 +1993,52 @@ static void renesas_eth_sw_remove(struct platform_device *pdev)
> > > > > >         platform_set_drvdata(pdev, NULL);
> > > > > >  }
> > > > > >
> > > > > > +static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
> > > > > > +{
> > > > > > +       struct rswitch_private *priv = dev_get_drvdata(dev);
> > > > > > +       struct net_device *ndev;
> > > > > > +       int i;
> > > > >
> > > > > unsigned int (also below)
> > > >
> > > > I don't know why unsigned int is needed. Other functions use
> > >
> > > There's this old mantra "prefer unsigned over signed in C",
> > > and a valid port array index here is always unsigned.
> >
> > I understood it.
> >
> > > > rswitch_for_each_enabled_port{_continue_reverse}() with int.
> > > > Especially, rswitch_for_each_enabled_port_continue_reverse()
> > > > has the following code, unsigned int will not work correctly:
> > >
> > > Oh, there is also a reverse variant, which indeed needs a signed
> > > iterator, currently...
> > >
> > > > ---
> > > > #define rswitch_for_each_enabled_port_continue_reverse(priv, i) \
> > > >         for (i--; i >= 0; i--)                                  \
> > >
> > > I think this can be made to work with an unsigned iterator using
> > >
> > >     for (; i-- > 0; )
> >
> > I think that this loop cannot access index 0 :)
> 
> rswitch_for_each_enabled_port_continue_reverse() is meant to be
> used in the error path, to tear down all ports that were initialized
> succesfully? So i is always the index of the first port that failed to
> initialize, i.e. i > 0 on entry.
> 
> See "git grep -Ww rswitch_for_each_enabled_port_continue_reverse".

Thank you for your comment. And I'm sorry, I completely misunderstood
about "for (; i-- > 0; )" behavior... I should have tested this before
I send such a comment...

Best regards,
Yoshihiro Shimoda

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c
index 0023ff254915..301053db61ac 100644
--- a/drivers/net/ethernet/renesas/rswitch.c
+++ b/drivers/net/ethernet/renesas/rswitch.c
@@ -17,6 +17,7 @@ 
 #include <linux/of_net.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/rtnetlink.h>
 #include <linux/slab.h>
@@ -1315,6 +1316,7 @@  static int rswitch_phy_device_init(struct rswitch_device *rdev)
 	if (!phydev)
 		goto out;
 	__set_bit(rdev->etha->phy_interface, phydev->host_interfaces);
+	phydev->mac_managed_pm = true;
 
 	phydev = of_phy_connect(rdev->ndev, phy, rswitch_adjust_link, 0,
 				rdev->etha->phy_interface);
@@ -1991,11 +1993,52 @@  static void renesas_eth_sw_remove(struct platform_device *pdev)
 	platform_set_drvdata(pdev, NULL);
 }
 
+static int __maybe_unused renesas_eth_sw_suspend(struct device *dev)
+{
+	struct rswitch_private *priv = dev_get_drvdata(dev);
+	struct net_device *ndev;
+	int i;
+
+	rswitch_for_each_enabled_port(priv, i) {
+		ndev = priv->rdev[i]->ndev;
+		if (netif_running(ndev)) {
+			netif_device_detach(ndev);
+			rswitch_stop(ndev);
+		}
+		if (priv->rdev[i]->serdes->init_count)
+			phy_exit(priv->rdev[i]->serdes);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused renesas_eth_sw_resume(struct device *dev)
+{
+	struct rswitch_private *priv = dev_get_drvdata(dev);
+	struct net_device *ndev;
+	int i;
+
+	rswitch_for_each_enabled_port(priv, i) {
+		phy_init(priv->rdev[i]->serdes);
+		ndev = priv->rdev[i]->ndev;
+		if (netif_running(ndev)) {
+			rswitch_open(ndev);
+			netif_device_attach(ndev);
+		}
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(renesas_eth_sw_pm_ops, renesas_eth_sw_suspend,
+			 renesas_eth_sw_resume);
+
 static struct platform_driver renesas_eth_sw_driver_platform = {
 	.probe = renesas_eth_sw_probe,
 	.remove_new = renesas_eth_sw_remove,
 	.driver = {
 		.name = "renesas_eth_sw",
+		.pm = &renesas_eth_sw_pm_ops,
 		.of_match_table = renesas_eth_sw_of_table,
 	}
 };