Re: [PATCH net-next 4/4] net: phy: mscc-miim: read poll when high resolution timers are disabled

From: Florian Fainelli
Date: Tue May 26 2020 - 18:05:44 EST




On 5/26/2020 3:01 PM, Andrew Lunn wrote:
>>> +/* When high resolution timers aren't built-in: we can't use usleep_range() as
>>> + * we would sleep way too long. Use udelay() instead.
>>> + */
>>> +#define mscc_readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
>>> +({ \
>>> + if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) \
>>> + readl_poll_timeout_atomic(addr, val, cond, delay_us, \
>>> + timeout_us); \
>>> + readl_poll_timeout(addr, val, cond, delay_us, timeout_us); \
>>> +})
>>> +
>>
>> I would make this a regular function which would not harm the compiler's
>> ability to optimize it, but would give you type checking. With that fixed:
>
> Hi Florian
>
> cond makes that difficult, since it is not a parameter in the usual
> sense, but an expression to evaluate if the polling should terminate.
>
> readl_poll_timeout() and readl_poll_timeout_atomic() themselves are
> #define's, and there are more levels of macros under them.

Oh that's right, thanks for reminding me of this.
--
Florian