Re: [PATCH net-next v2 1/2] drivers: net: stmmac: handle start time set in the past for flexible PPS

[Gatien CHEVALLIER <gatien.chevallier@foss.st.com>]

On 7/29/25 18:58, Simon Horman wrote:
> On Tue, Jul 29, 2025 at 04:52:00PM +0200, Gatien Chevallier wrote:
>> In case the time arguments used for flexible PPS signal generation are in
>> the past, consider the arguments to be a time offset relative to the MAC
>> system time.
>>
>> This way, past time use case is handled and it avoids the tedious work
>> of passing an absolute time value for the flexible PPS signal generation
>> while not breaking existing scripts that may rely on this behavior.
>>
>> Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
>> ---
>>   drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c | 31 ++++++++++++++++++++++++
>>   1 file changed, 31 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
>> index 3767ba495e78d210b0529ee1754e5331f2dd0a47..5c712b33851081b5ae1dbf2a0988919ae647a9e2 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
>> @@ -10,6 +10,8 @@
>>   #include "stmmac.h"
>>   #include "stmmac_ptp.h"
>>   
>> +#define PTP_SAFE_TIME_OFFSET_NS	500000
>> +
>>   /**
>>    * stmmac_adjust_freq
>>    *
>> @@ -172,6 +174,10 @@ static int stmmac_enable(struct ptp_clock_info *ptp,
>>   
>>   	switch (rq->type) {
>>   	case PTP_CLK_REQ_PEROUT:
>> +		struct timespec64 curr_time;
>> +		u64 target_ns = 0;
>> +		u64 ns = 0;
>> +
> 
> I think you need to wrap this case in {}, as is already done for the following
> case.
> 
> Clang 20.1.8 W=1 build warn about the current arrangement as follows.
> 
>    .../stmmac_ptp.c:177:3: warning: label followed by a declaration is a C23 extension [-Wc23-extensions]
>      177 |                 struct timespec64 curr_time;
>          |                 ^
>    1 warning generated.
> 
> GCC 8.5.0 (but not 15.1.0) also flags this problem.
> 

Hello Simon,

Ok I will comply for V3.

> Also, please note:
> 
> ## Form letter - net-next-closed
> 
> The merge window for v6.17 has begun and therefore net-next is closed
> for new drivers, features, code refactoring and optimizations. We are
> currently accepting bug fixes only.
> 
> Please repost when net-next reopens after 11th August.
> 
> RFC patches sent for review only are obviously welcome at any time.
> 
> See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle
> 

Thank you for pointing this out.

Best regards,
Gatien