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SubjectRe: [PATCH] net: macb: fix endian code for avr32
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On Wed, Mar 18, 2015 at 6:46 PM, Arun Chandran <achandran@mvista.com> wrote:
> On Wed, Mar 18, 2015 at 4:27 PM, Ben Dooks <ben.dooks@codethink.co.uk> wrote:
>>
>> [note this has yet to be compile tested on avr32]
>>
>> The changes to run the macb driver in 29af05aeb98e ("net: macb:
>
> Yes I mistakenly thought zynq board was the first to run it in
> BIG endian mode.
>
>> Add big endian CPU support") to support big endian operation on
>> ARM may not work on AVR32 which already is naturally big endian
>> architecture (and the driver already works here).
>>
>> In this case the readl/writel relaxed will do the opposite of __raw
>> accesors which arleady work. Add an indirection of cdneth_ prefixed
>> accesors which are changed as necessary. Also do not issue the DMA
>> descritpor endian fetch configuration for AVR32.
>>
>> From discussions with Arnd Bergman, the following fix changes the use
>> of readl_relaxed and writel_relaxed with a version that can be put
>> back to __raw_readl/__raw_writel for the CONFIG_AVR32 case (and also
>> remove the change to the DMA descriptor endian).
>>
>> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
>> Reported-by: Arnd Bergmann <arnd@arndb.de>
>> --
>> CC: Linux Networking List <netdev@vger.kernel.org>
>> CC: Arun Chandran <achandran@mvista.com>
>> CC: Haavard Skinnemoen <hskinnemoen@gmail.com>
>> CC: Hans-Christian Egtvedt <egtvedt@samfundet.no>
>> CC: Linux Kernel List <linux-kernel@vger.kernel.org>
>> CC: Nicolas Ferre <nicolas.ferre@atmel.com>
>> ---
>> drivers/net/ethernet/cadence/macb.c | 14 +++++++-------
>> drivers/net/ethernet/cadence/macb.h | 20 ++++++++++++++------
>> 2 files changed, 21 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
>> index b71e316..1c3f6e7 100644
>> --- a/drivers/net/ethernet/cadence/macb.c
>> +++ b/drivers/net/ethernet/cadence/macb.c
>> @@ -449,7 +449,7 @@ static void macb_update_stats(struct macb *bp)
>> WARN_ON((unsigned long)(end - p - 1) != (MACB_TPF - MACB_PFR) / 4);
>>
>> for(; p < end; p++, reg++)
>> - *p += readl_relaxed(reg);
>> + *p += cdneth_readl(reg);
>> }
>>
>> static int macb_halt_tx(struct macb *bp)
>> @@ -1587,7 +1587,7 @@ static void macb_configure_dma(struct macb *bp)
>> dmacfg |= GEM_BIT(TXPBMS) | GEM_BF(RXBMS, -1L);
>> dmacfg &= ~GEM_BIT(ENDIA_PKT);
>> /* Tell the chip to byteswap descriptors on big-endian hosts */
>> -#ifdef __BIG_ENDIAN
>
>
> With https://kernel.googlesource.com/pub/scm/linux/kernel/git/davem/net-next/+/62f6924cb1543a10d05150d77f9a5e01e12c9ce1
> in net-next I think CONFIG_AVR32 check is not required.
>
> --Arun

I mean only the below check for dmacfg is not required

/* Tell the chip to byteswap descriptors on big-endian hosts */
-#ifdef __BIG_ENDIAN
+#if defined(__BIG_ENDIAN) && !defined(CONFIG_AVR32)
dmacfg |= GEM_BIT(ENDIA_DESC);
#endif

--Arun


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