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

From: Guenter Roeck <[email-masked]>
Date: Fri, 25 Mar 2016 19:42:35 -0700

On 03/25/2016 06:58 PM, Patrick Uiterwijk wrote:
> On Sat, Mar 26, 2016 at 2:45 AM, Guenter Roeck <[email-masked]> 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 <[email-masked]>
>>> ---
>>>    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;
>>>    }
>>>
>>>
>>
>