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

[Hemant Agrawal]

On 9/17/2020 5:08 PM, Ferruh Yigit wrote:
> On 9/17/2020 3:03 AM, Di, ChenxuX wrote:
>> Hi,
>>
>>> -----Original Message-----
>>> From: Ferruh Yigit <ferruh.yigit at intel.com>
>>> Sent: Wednesday, September 16, 2020 11:29 PM
>>> To: Di, ChenxuX <chenxux.di at intel.com>; hemant.agrawal at nxp.com
>>> Cc: sachin.saxena at nxp.com; stable at dpdk.org; dev at dpdk.org; Richardson,
>>> Bruce <bruce.richardson at 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 at dpdk.org
>>>>
>>>> Signed-off-by: Chenxu Di <chenxux.di at 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.

Hi Ferruh,

    enabling  IEEE1588 causes some performance drop in the dpaa2 
performance. That is the reason, we have kept this code in compile time 
flag.


However, we will work in future to make it run-time configurable but 
that will require some code restructuring and it will be a moderate size 
work.


Regards,

Hemant