macb: zynq: why is SG disabled?

macb: zynq: why is SG disabled?

[Nicolae Rosia]

Hello,

After reading the GEM part of Zynq7000 Technical Reference Manual [0], I 
think that SG should be supported.
Is there a reason why SG is disabled in macb for Zynq?

Best regards,
Nicolae Rosia

Re: macb: zynq: why is SG disabled?

[Cyrille Pitchen]

Le 01/07/2015 17:14, Nicolae Rosia a écrit :
> Hello,
> 
> After reading the GEM part of Zynq7000 Technical Reference Manual [0], I think that SG should be supported.
> Is there a reason why SG is disabled in macb for Zynq?
> 
> Best regards,
> Nicolae Rosia

Hi Nicolae,

when the scatter-gather patch was introduced, the feature was enabled only on
tested boards to avoid regressions on other boards.
So SG is enabled on sama5d4x and sama5d2x SoCs. SG is disabled on purpose on
sama5d3x.

For Zynq, I think the feature is still disabled just because it has never been
tested.

Best regards,

Cyrille

RE: macb: zynq: why is SG disabled?

[Punnaiah Choudary Kalluri]

Hi Nicolae and Cyrille,

   SG feature was not tested for Zynq using macb driver but tested it using the
 emacps Driver in Xilinx tree (this driver is deprecated recently)

We will test and enable this feature in driver for Zynq.

Regards,
Punnaiah

> -----Original Message-----
> From: Cyrille Pitchen [mailto:cyrille.pitchen@atmel.com]
> Sent: Wednesday, July 01, 2015 10:34 PM
> To: Nicolae Rosia; Michal Simek; Punnaiah Choudary Kalluri;
> netdev@vger.kernel.org; Nicolas Ferre; linux-arm-kernel@lists.infradead.org
> Subject: Re: macb: zynq: why is SG disabled?
> 
> Le 01/07/2015 17:14, Nicolae Rosia a écrit :
> > Hello,
> >
> > After reading the GEM part of Zynq7000 Technical Reference Manual [0], I
> think that SG should be supported.
> > Is there a reason why SG is disabled in macb for Zynq?
> >
> > Best regards,
> > Nicolae Rosia
> 
> Hi Nicolae,
> 
> when the scatter-gather patch was introduced, the feature was enabled only
> on tested boards to avoid regressions on other boards.
> So SG is enabled on sama5d4x and sama5d2x SoCs. SG is disabled on purpose
> on sama5d3x.
> 
> For Zynq, I think the feature is still disabled just because it has never been
> tested.
> 
> Best regards,
> 
> Cyrille

Re: macb: zynq: why is SG disabled?

[Nicolas Ferre]

Le 02/07/2015 04:33, Punnaiah Choudary Kalluri a écrit :
> Hi Nicolae and Cyrille,
> 
>    SG feature was not tested for Zynq using macb driver but tested it using the
>  emacps Driver in Xilinx tree (this driver is deprecated recently)
> 
> We will test and enable this feature in driver for Zynq.

Ok, fine: we will be glad to merge patches that would enable this
feature on Zynq.

Bye,


>> -----Original Message-----
>> From: Cyrille Pitchen [mailto:cyrille.pitchen@atmel.com]
>> Sent: Wednesday, July 01, 2015 10:34 PM
>> To: Nicolae Rosia; Michal Simek; Punnaiah Choudary Kalluri;
>> netdev@vger.kernel.org; Nicolas Ferre; linux-arm-kernel@lists.infradead.org
>> Subject: Re: macb: zynq: why is SG disabled?
>>
>> Le 01/07/2015 17:14, Nicolae Rosia a écrit :
>>> Hello,
>>>
>>> After reading the GEM part of Zynq7000 Technical Reference Manual [0], I
>> think that SG should be supported.
>>> Is there a reason why SG is disabled in macb for Zynq?
>>>
>>> Best regards,
>>> Nicolae Rosia
>>
>> Hi Nicolae,
>>
>> when the scatter-gather patch was introduced, the feature was enabled only
>> on tested boards to avoid regressions on other boards.
>> So SG is enabled on sama5d4x and sama5d2x SoCs. SG is disabled on purpose
>> on sama5d3x.
>>
>> For Zynq, I think the feature is still disabled just because it has never been
>> tested.
>>
>> Best regards,
>>
>> Cyrille
> 


-- 
Nicolas Ferre