Re: [PATCHv2] gianfar: Add gfar_change_carrier() for Fixed PHYs

[Joakim Tjernlund]

On Wed, 2018-12-12 at 15:51 +0100, Andrew Lunn wrote:
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> 
> > fast check, would you be happy with this in fixed PHY:
> > --- a/drivers/net/phy/fixed_phy.c
> > +++ b/drivers/net/phy/fixed_phy.c
> > @@ -25,6 +25,7 @@
> >  #include <linux/gpio.h>
> >  #include <linux/seqlock.h>
> >  #include <linux/idr.h>
> > +#include <linux/netdevice.h>
> > 
> >  #include "swphy.h"
> > 
> > @@ -38,6 +39,7 @@ struct fixed_phy {
> >         struct phy_device *phydev;
> >         seqcount_t seqcount;
> >         struct fixed_phy_status status;
> > +       bool no_carrier;
> >         int (*link_update)(struct net_device *, struct fixed_phy_status *);
> >         struct list_head node;
> >         int link_gpio;
> > @@ -48,6 +50,24 @@ static struct fixed_mdio_bus platform_fmb = {
> >         .phys = LIST_HEAD_INIT(platform_fmb.phys),
> >  };
> > 
> > +int
> > +fixed_phy_change_carrier(struct net_device *dev, bool new_carrier)
> > +{
> > +       struct fixed_mdio_bus *fmb = &platform_fmb;
> > +       struct phy_device *phydev = dev->phydev;
> > +       struct fixed_phy *fp;
> > +
> > +       if (!phydev || !phydev->mdio.bus)
> > +               return -EINVAL;
> > +
> > +       list_for_each_entry(fp, &fmb->phys, node) {
> > +               if (fp->addr == phydev->mdio.addr) {
> > +                       fp->no_carrier = !new_carrier;
> 
> Why is no_carrier needed? You can directly change fp->status.link, so
> long as you take care of locking.

I to remember it for the gpio control of link state, see below.

> 
> > +                       return 0;
> > +               }
> > +       }
> > +       return -EINVAL;
> > +}
> 
> You need to export the function.

Yes, it was not a complete patch. Below is what I have now and is happy with:

diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c
index eb5167210681..aedebc251997 100644
--- a/drivers/net/phy/fixed_phy.c
+++ b/drivers/net/phy/fixed_phy.c
@@ -25,6 +25,7 @@
 #include <linux/gpio.h>
 #include <linux/seqlock.h>
 #include <linux/idr.h>
+#include <linux/netdevice.h>
 
 #include "swphy.h"
 
@@ -38,6 +39,7 @@ struct fixed_phy {
        struct phy_device *phydev;
        seqcount_t seqcount;
        struct fixed_phy_status status;
+       bool no_carrier;
        int (*link_update)(struct net_device *, struct fixed_phy_status *);
        struct list_head node;
        int link_gpio;
@@ -48,9 +50,27 @@ static struct fixed_mdio_bus platform_fmb = {
        .phys = LIST_HEAD_INIT(platform_fmb.phys),
 };
 
+int
+fixed_phy_change_carrier(struct net_device *dev, bool new_carrier)
+{
+       struct fixed_mdio_bus *fmb = &platform_fmb;
+       struct phy_device *phydev = dev->phydev;
+       struct fixed_phy *fp;
+
+       if (!phydev || !phydev->mdio.bus)
+               return -EINVAL;
+
+       list_for_each_entry(fp, &fmb->phys, node) {
+               if (fp->addr == phydev->mdio.addr) {
+                       fp->no_carrier = !new_carrier;
+                       return 0;
+               }
+       }
+       return -EINVAL;
+}
 static void fixed_phy_update(struct fixed_phy *fp)
 {
-       if (gpio_is_valid(fp->link_gpio))
+       if (!fp->no_carrier && gpio_is_valid(fp->link_gpio))
                fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
 }
 
@@ -66,6 +86,7 @@ static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, 
int reg_num)
 
                        do {
                                s = read_seqcount_begin(&fp->seqcount);
+                               fp->status.link = !fp->no_carrier;
                                /* Issue callback if user registered it. */
                                if (fp->link_update) {
                                        
fp->link_update(fp->phydev->attached_dev,
diff --git a/include/linux/phy_fixed.h b/include/linux/phy_fixed.h
index cf6392de6eb0..09d7e613cffc 100644
--- a/include/linux/phy_fixed.h
+++ b/include/linux/phy_fixed.h
@@ -27,6 +27,7 @@ extern int fixed_phy_set_link_update(struct phy_device 
*phydev,
 extern int fixed_phy_update_state(struct phy_device *phydev,
                           const struct fixed_phy_status *status,
                           const struct fixed_phy_status *changed);
+extern int fixed_phy_change_carrier(struct net_device *dev, bool new_carrier);
 #else
 static inline int fixed_phy_add(unsigned int irq, int phy_id,
                                struct fixed_phy_status *status,
@@ -56,6 +57,10 @@ static inline int fixed_phy_update_state(struct phy_device 
*phydev,
 {
        return -ENODEV;
 }
+static inline int fixed_phy_change_carrier(struct net_device *dev, bool 
new_carrier)
+{
+       return -EINVAL;
+}
 #endif /* CONFIG_FIXED_PHY */
 
 #endif /* __PHY_FIXED_H */
-- 
2.18.1