macb: zynq: why is SG disabled?

Nicolas Ferre nicolas.ferre at
Thu Jul 2 00:48:34 PDT 2015

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.


>> -----Original Message-----
>> From: Cyrille Pitchen [mailto:cyrille.pitchen at]
>> Sent: Wednesday, July 01, 2015 10:34 PM
>> To: Nicolae Rosia; Michal Simek; Punnaiah Choudary Kalluri;
>> netdev at; Nicolas Ferre; linux-arm-kernel at
>> 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

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