Re: [PATCH 1/2] net: dsa: mv88e6xxx: Introduce _mv88e6xxx_phy_page_{read,write}

[Guenter Roeck]

On 03/25/2016 06:58 PM, Patrick Uiterwijk wrote:

On Sat, Mar 26, 2016 at 2:45 AM, Guenter Roeck <li...@roeck-us.net> wrote:

On 03/25/2016 05:10 PM, Patrick Uiterwijk wrote:

Add versions of the phy_page_read and _write functions to
be used in a context where the SMI mutex is held.

Signed-off-by: Patrick Uiterwijk <patr...@puiterwijk.org>
---
   drivers/net/dsa/mv88e6xxx.c | 42
++++++++++++++++++++++++++++++++----------
   1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index fa086e0..13db5d8 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -2708,37 +2708,59 @@ int mv88e6xxx_switch_reset(struct dsa_switch *ds,
bool ppu_active)
         return 0;
   }

-int mv88e6xxx_phy_page_read(struct dsa_switch *ds, int port, int page,
int reg)
+static int _mv88e6xxx_phy_page_read(struct dsa_switch *ds, int port, int
page,
+                                   int reg)
   {
-       struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
         int ret;

-       mutex_lock(&ps->smi_mutex);
         ret = _mv88e6xxx_phy_write_indirect(ds, port, 0x16, page);
         if (ret < 0)
-               goto error;
+               goto clear;
         ret = _mv88e6xxx_phy_read_indirect(ds, port, reg);
-error:
+clear:

Is there some good reason for changing the name of those labels ?

Vivien suggested to rename this since it makes more clear that this write is
meant to return to page 0 to make sure that phylib doesn't get confused
about the currently active page.

And "clear:" accomplishes that ? I would not have guessed.
Wonder if anyone else does. I would have used a comment.
        /* Try to return to page 0 even after an error */
or something like that.

Guenter

Patrick

Guenter

         _mv88e6xxx_phy_write_indirect(ds, port, 0x16, 0x0);
-       mutex_unlock(&ps->smi_mutex);
+
         return ret;
   }

-int mv88e6xxx_phy_page_write(struct dsa_switch *ds, int port, int page,
-                            int reg, int val)
+int mv88e6xxx_phy_page_read(struct dsa_switch *ds, int port, int page,
int reg)
   {
         struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
         int ret;

         mutex_lock(&ps->smi_mutex);
+       ret = _mv88e6xxx_phy_page_read(ds, port, page, reg);
+       mutex_unlock(&ps->smi_mutex);
+
+       return ret;
+}
+
+static int _mv88e6xxx_phy_page_write(struct dsa_switch *ds, int port, int
page,
+                                    int reg, int val)
+{
+       int ret;
+
         ret = _mv88e6xxx_phy_write_indirect(ds, port, 0x16, page);
         if (ret < 0)
-               goto error;
+               goto clear;

         ret = _mv88e6xxx_phy_write_indirect(ds, port, reg, val);
-error:
+clear:
         _mv88e6xxx_phy_write_indirect(ds, port, 0x16, 0x0);
+
+       return ret;
+}
+
+int mv88e6xxx_phy_page_write(struct dsa_switch *ds, int port, int page,
+                            int reg, int val)
+{
+       struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+       int ret;
+
+       mutex_lock(&ps->smi_mutex);
+       ret = _mv88e6xxx_phy_page_write(ds, port, page, reg, val);
         mutex_unlock(&ps->smi_mutex);
+
         return ret;
   }