On 2/15/19 10:34 AM, Paul Kocialkowski wrote:
> Hi,
>
> On Fri, 2019-02-15 at 09:38 -0800, Florian Fainelli wrote:
>> On 2/15/19 8:32 AM, Paul Kocialkowski wrote:
>>> Some PHY drivers like the generic one do not provide a read_status
>>> callback on their own but rely on genphy_read_status being called
>>> directly.
>>>
>>> With the current code, this results in a NULL function pointer call.
>>> Call genphy_read_status instead when there is no specific callback.
>>>
>>> Fixes: f411a6160bd4 ("net: phy: Add gmiitorgmii converter support")
>>> Signed-off-by: Paul Kocialkowski <paul.kocialkow...@bootlin.com>
>>> ---
>>> Added Fixes tag and net label for resend.
>>
>> You would want to use phy_read_status() which encapsulates that check as
>> well as checks that the phy_drv pointer is not NULL.
>
> Well, this driver is a bit different and our priv->phy_drv != phydev-
>> drv, so we can't use the helper directly. I should probably have
> mentionned it in the commit message, sorry!
>
> As I was mentionning to Andrew in the initial submission of this patch,
> this driver is a bit unusual since it represents a GMII to RGMII
> bridge, so it's not actually a PHY driver on its own -- it just sticks
> itself in between the actual PHY and the MAC.
Yes, my bad, you should still consider checking priv->phy_drv though, if
someone unbinds the PHY driver on either side, you are toast.
>
> Cheers and thanks for the review,
>
> Paul
>
>>> drivers/net/phy/xilinx_gmii2rgmii.c | 5 ++++-
>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c
>>> b/drivers/net/phy/xilinx_gmii2rgmii.c
>>> index 74a8782313cf..bd6084e315de 100644
>>> --- a/drivers/net/phy/xilinx_gmii2rgmii.c
>>> +++ b/drivers/net/phy/xilinx_gmii2rgmii.c
>>> @@ -44,7 +44,10 @@ static int xgmiitorgmii_read_status(struct phy_device
>>> *phydev)
>>> u16 val = 0;
>>> int err;
>>>
>>> - err = priv->phy_drv->read_status(phydev);
>>> + if (priv->phy_drv->read_status)
>>> + err = priv->phy_drv->read_status(phydev);
>>> + else
>>> + err = genphy_read_status(phydev);
>>> if (err < 0)
>>> return err;
>>>
>>>
>>
>>
--
Florian
