Re: [PATCH net] net: phy: smsc: add missed clk_disable_unprepare in smsc_phy_probe()

From: Florian Fainelli
Date: Sat Nov 14 2020 - 14:46:04 EST




On 11/14/2020 11:26 AM, Jakub Kicinski wrote:
> On Thu, 12 Nov 2020 19:23:59 +0800 Zhang Changzhong wrote:
>> Add the missing clk_disable_unprepare() before return from
>> smsc_phy_probe() in the error handling case.
>>
>> Fixes: bedd8d78aba3 ("net: phy: smsc: LAN8710/20: add phy refclk in support")
>> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
>> Signed-off-by: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>
>> ---
>> drivers/net/phy/smsc.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
>> index ec97669..0fc39ac 100644
>> --- a/drivers/net/phy/smsc.c
>> +++ b/drivers/net/phy/smsc.c
>> @@ -291,8 +291,10 @@ static int smsc_phy_probe(struct phy_device *phydev)
>> return ret;
>>
>> ret = clk_set_rate(priv->refclk, 50 * 1000 * 1000);
>> - if (ret)
>> + if (ret) {
>> + clk_disable_unprepare(priv->refclk);
>> return ret;
>> + }
>>
>> return 0;
>> }
>
> Applied, thanks!
>
> The code right above looks highly questionable as well:
>
> priv->refclk = clk_get_optional(dev, NULL);
> if (IS_ERR(priv->refclk))
> dev_err_probe(dev, PTR_ERR(priv->refclk), "Failed to request clock\n");
>
> ret = clk_prepare_enable(priv->refclk);
> if (ret)
> return ret;
>
> I don't think clk_prepare_enable() will be too happy to see an error
> pointer. This should probably be:
>
> priv->refclk = clk_get_optional(dev, NULL);
> if (IS_ERR(priv->refclk))
> return dev_err_probe(dev, PTR_ERR(priv->refclk),
> "Failed to request clock\n");

Right, especially if EPROBE_DEFER must be returned because the clock
provider is not ready yet, we should have a chance to do that.
--
Florian