Re: [Qemu-devel] [PATCH 07/17] imx_fec: Emulate SHIFT16 in ENETx_RACC

[Andrey Smirnov <andrew.smirnov@gmail.com>]

On Fri, Oct 6, 2017 at 7:02 AM, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 18 September 2017 at 20:50, Andrey Smirnov <andrew.smirnov@gmail.com> wrote:
>> Needed to support latest Linux kernel driver which relies on that
>> functionality.
>>
>> Cc: Peter Maydell <peter.maydell@linaro.org>
>> Cc: Jason Wang <jasowang@redhat.com>
>> Cc: qemu-devel@nongnu.org
>> Cc: qemu-arm@nongnu.org
>> Cc: yurovsky@gmail.com
>> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
>> ---
>>  hw/net/imx_fec.c         | 23 +++++++++++++++++++++++
>>  include/hw/net/imx_fec.h |  2 ++
>>  2 files changed, 25 insertions(+)
>>
>> diff --git a/hw/net/imx_fec.c b/hw/net/imx_fec.c
>> index 8a77136d38..bd62d7a75f 100644
>> --- a/hw/net/imx_fec.c
>> +++ b/hw/net/imx_fec.c
>> @@ -1037,6 +1037,7 @@ static ssize_t imx_enet_receive(NetClientState *nc, const uint8_t *buf,
>>      uint32_t buf_addr;
>>      unsigned int buf_len;
>>      size_t size = len;
>> +    bool shift16 = s->regs[ENET_RACC] & ENET_RACC_SHIFT16;
>>
>>      FEC_PRINTF("len %d\n", (int)size);
>>
>> @@ -1049,6 +1050,10 @@ static ssize_t imx_enet_receive(NetClientState *nc, const uint8_t *buf,
>>      /* 4 bytes for the CRC.  */
>>      size += 4;
>>
>> +    if (shift16) {
>> +        size += 2;
>> +    }
>> +
>>      /* Huge frames are truncted.  */
>>      if (size > s->regs[ENET_FTRL]) {
>>          size = s->regs[ENET_FTRL];
>> @@ -1085,6 +1090,24 @@ static ssize_t imx_enet_receive(NetClientState *nc, const uint8_t *buf,
>>              buf_len += size - 4;
>>          }
>>          buf_addr = bd.data;
>> +
>> +        if (shift16) {
>> +            /*
>> +             * If SHIFT16 bit of ENETx_RACC register is set we need to
>> +             * align the payload to 4-byte boundary.
>> +             */
>> +            const uint8_t zeros[2] = { 0 };
>> +
>> +            dma_memory_write(&address_space_memory, buf_addr,
>> +                             zeros, sizeof(zeros));
>> +
>> +            buf_addr += sizeof(zeros);
>> +            buf_len  -= sizeof(zeros);
>> +
>> +            shift16 = false; /* We only do this once per Ethernet
>> +                              * frame */
>> +        }
>> +
>
> Can you avoid having an end-of-source-line comment that wraps
> to multiple lines, please? (put it on a line of its own, or
> edit down to fit.) Otherwise
>

Sure, will fix in v2.

Thanks,
Andrey Smirnov