Re: [dpdk-stable] [PATCH] net/dpaa2: fix build error about timesync functions

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 9/17/2020 3:03 AM, Di, ChenxuX wrote:
> Hi,
> 
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>> Sent: Wednesday, September 16, 2020 11:29 PM
>> To: Di, ChenxuX <chenxux.di@intel.com>; hemant.agrawal@nxp.com
>> Cc: sachin.saxena@nxp.com; stable@dpdk.org; dev@dpdk.org; Richardson,
>> Bruce <bruce.richardson@intel.com>
>> Subject: Re: [dpdk-stable] [PATCH] net/dpaa2: fix build error about timesync
>> functions
>>
>> On 9/15/2020 3:40 AM, Chenxu Di wrote:
>>> When the build option has '-DRTE_LIBRTE_IEEE1588=1', the announce of
>>> timesync functions will be build.
>>> However the dpdk_conf doesn't hav RTE_LIBRTE_IEEE1588 so that the file
>>> dpaa2_ptp.c will not be build.
>>> It cause the build error.
>>> This patch fixes it by adding set for dpdk_conf.
>>>
>>> Fixes: 184c39d16568 ("net/dpaa2: add DPRTC sub-module")
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Chenxu Di <chenxux.di@intel.com>
>>> ---
>>>    drivers/net/dpaa2/meson.build | 4 ++++
>>>    1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/net/dpaa2/meson.build
>>> b/drivers/net/dpaa2/meson.build index 6dd0eb274..d9aadfdae 100644
>>> --- a/drivers/net/dpaa2/meson.build
>>> +++ b/drivers/net/dpaa2/meson.build
>>> @@ -17,6 +17,10 @@ sources = files('base/dpaa2_hw_dpni.c',
>>>    		'mc/dpdmux.c',
>>>    		'mc/dpni.c')
>>>
>>> +if '-DRTE_LIBRTE_IEEE1588=1' in get_option('c_args')
>>
>> The "RTE_LIBRTE_IEEE1588=1" can fail,
>> all places looking for "#ifdef RTE_LIBRTE_IEEE1588", so a "-Dc_args=-
>> DRTE_LIBRTE_IEEE1588" is more likely, but why not "-Dc_args=-
>> DRTE_LIBRTE_IEEE1588=666"
>>
> 
> Yes, I will change it
> 
>>> +	dpdk_conf.set('RTE_LIBRTE_IEEE1588', 1) endif
>>> +
>>>    if dpdk_conf.has('RTE_LIBRTE_IEEE1588')
>>>    	sources += files('mc/dprtc.c')
>>>    	sources += files('dpaa2_ptp.c')
>>>
>>
>> Can't we just remove the conditional build:
>>
>>    -if dpdk_conf.has('RTE_LIBRTE_IEEE1588')
>>    -       sources += files('mc/dprtc.c')
>>    -       sources += files('dpaa2_ptp.c')
>>    -endif
>>    +sources += files('mc/dprtc.c')
>>    +sources += files('dpaa2_ptp.c')
> 
> The announce of timesync functions are in the #define DRTE_LIBRTE_IEEE1588
> While the define of the functions are in the file 'dpaa2_ptp.c'.
> So they should be both build or not build by whether the build option -DRTE_LIBRTE_IEEE1588=1 or not.
> So it seems not a good idea that remove the conditional.
> 

timesyncs_* dev_ops functions defined but not used is not big problem, 
only can increase the library size.

I believe more concern is on:
'RTE_PMD_REGISTER_DPAA2_OBJECT(dprtc, rte_dpaa2_dprtc_obj);'
which looks like register function to run in constructor when 
'dpaa2_ptp.c' is compiled, but not sure affect of it.
It can be possible to wrap that call with 'RTE_LIBRTE_IEEE1588' ifdef, 
that should work.

It is preferred to remove the compile time flag instead of finding ways 
to make it work.

Let's wait for the dpaa2 maintainers' response, perhaps they can come 
with a smart way to remove the compile time flag.