Re: [PATCH] include: linux/iopoll.h: silence warning when timeout_us contains *

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hello Sascha,

On 10.01.23 15:41, Sascha Hauer wrote:
> On Mon, Jan 09, 2023 at 05:00:57PM +0100, Ahmad Fatoum wrote:
>> We evaluate timeout_us for truthiness to determine whether we are
>> entering an infinite poll loop. When timeout_us contains a
>> multiplication, GCC will warn about it and suggest replacing the *
>> with &&. Silence this warning by comparing directly against 0.
>>
>> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
>> ---
>>  include/linux/iopoll.h | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
>> index 8bf912e173b3..b8c55583f97f 100644
>> --- a/include/linux/iopoll.h
>> +++ b/include/linux/iopoll.h
>> @@ -32,13 +32,13 @@
>>  #define read_poll_timeout(op, val, cond, timeout_us, args...)	\
>>  ({ \
>>  	uint64_t start; \
>> -	if (!IN_PBL && timeout_us) \
>> +	if (!IN_PBL && timeout_us != 0) \
> 
> You should rather put timeout_us in brackets.

Doesn't help:

  drivers/mtd/nand/atmel/nand-controller.c:279:51:
    warning: '*' in boolean context, suggest '&&' instead [-Wint-in-bool-context]
    279 |                                        timeout_ms * 1000);                                                                           
  include/linux/iopoll.h:35:25: note: in definition of macro 'read_poll_timeout'                      
     35 |         if (!IN_PBL && (timeout_us)) \                                                                                               
        |                         ^~~~~~~~~~                                                                                                   

Ok to apply?

Cheers,
Ahmad

> 
> Sascha
> 
>>  		start = get_time_ns(); \
>>  	for (;;) { \
>>  		(val) = op(args); \
>>  		if (cond) \
>>  			break; \
>> -		if (!IN_PBL && timeout_us && \
>> +		if (!IN_PBL && timeout_us != 0 && \
>>  		    is_timeout(start, ((timeout_us) * USECOND))) { \
>>  			(val) = op(args); \
>>  			break; \
>> -- 
>> 2.30.2
>>
>>
>>
> 

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