[U-Boot] [PATCH] net: configure DWMAC DMA by default AXI burst length

[Sonic Zhang]

Hi Joe,

On Wed, Jan 28, 2015 at 5:42 PM, Joe Hershberger
<joe.hershberger at gmail.com> wrote:
> On Tue, Jan 27, 2015 at 9:24 PM, Sonic Zhang <sonic.adi at gmail.com> wrote:
>>
>> Hi Joe,
>>
>> On Wed, Jan 28, 2015 at 4:43 AM, Joe Hershberger
>> <joe.hershberger at gmail.com> wrote:
>> > On Mon, Jan 26, 2015 at 8:54 PM, <sonic.adi at gmail.com> wrote:
>> >>
>> >> From: Sonic Zhang <sonic.zhang at analog.com>
>> >>
>> >> Board can define its own AXI burst length to improve DWMAC DMA
>> >> performance.
>> >>
>> >> Signed-off-by: Sonic Zhang <sonic.zhang at analog.com>
>> >> ---
>> >>
>> >>  drivers/net/designware.c |    2 ++
>> >>  drivers/net/designware.h |    5 +++++
>> >>  2 files changed, 7 insertions(+)
>> >>
>> >> diff --git a/drivers/net/designware.c b/drivers/net/designware.c
>> >> index 9ded895..d8d6792 100644
>> >> --- a/drivers/net/designware.c
>> >> +++ b/drivers/net/designware.c
>> >> @@ -256,6 +256,8 @@ static int dw_eth_init(struct eth_device *dev, bd_t
>> >> *bis)
>> >>
>> >>         writel(readl(&dma_p->opmode) | RXSTART | TXSTART,
>> >> &dma_p->opmode);
>> >>
>> > This should probably include:
>> > +#if CONFIG_DW_AXI_BURST_LEN
>> > so that this register is only accessed if configured.
>>
>> CONFIG_DW_AXI_BURST_LEN is always defined in designware.h in the same
>> patch.
>>
>> +/* Default AXI BUS Burst length */
>> +#ifndef CONFIG_DW_AXI_BURST_LEN
>> +#define CONFIG_DW_AXI_BURST_LEN 0
>> +#endif
>> +
>
> Yes, I saw that... sorry I wasn't clear.  I meant don't we want to avoid the
> write (preserving existing behavior) instead of ensuring that it is set, and
> still adding a register write that is (presumably) a NOP?
OK, I will update the patch.

Sonic