Re: [PATCH net-next v6 07/10] net: phy: introduce phy_read_poll_timeout macro

[Florian Fainelli <f.fainelli@gmail.com>]

On 3/22/2020 7:56 PM, Dejin Zheng wrote:
> it is sometimes necessary to poll a phy register by phy_read()
> function until its value satisfies some condition. introduce
> phy_read_poll_timeout() macros that do this.
> 
> Suggested-by: Andrew Lunn <andrew@lunn.ch>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
> ---
> v5 -> v6:
> 	- no changed.
> v4 -> v5:
> 	- no changed.
> v3 -> v4:
> 	- deal with precedence issues for parameter cond.
> v2 -> v3:
> 	- modify the parameter order of newly added functions.
> 	  phy_read_poll_timeout(val, cond, sleep_us, timeout_us, \
> 				phydev, regnum)
> 				||
> 				\/
> 	  phy_read_poll_timeout(phydev, regnum, val, cond, sleep_us, \
> 				timeout_us)
> v1 -> v2:
> 	- pass a phydev and a regnum to replace args... parameter in
> 	  the phy_read_poll_timeout(), and also handle the
> 	  phy_read() function's return error.
>  
>  include/linux/phy.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index 42a5ec9288d5..f2e0aea13a2f 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -714,6 +714,19 @@ static inline int phy_read(struct phy_device *phydev, u32 regnum)
>  	return mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, regnum);
>  }
>  
> +#define phy_read_poll_timeout(phydev, regnum, val, cond, sleep_us, timeout_us) \
> +({ \
> +	int ret = 0; \
> +	ret = read_poll_timeout(phy_read, val, (cond) || val < 0, sleep_us, \
> +				timeout_us, phydev, regnum); \
> +	if (val <  0) \
> +		ret = val; \
> +	if (ret) \
> +		phydev_err(phydev, "%s failed: %d\n", __func__, ret); \> +	ret; \

Those variable names are likely going to be clashing with existing
variables within a function, I would recommend you prefix with double
underscores: __ret, __val to avoid any variable re-declaration or shadowing.
-- 
Florian