Re: [Qemu-devel] [PATCH 05/17] imx_fec: Use ENET_FTRL to determine truncation length

[Philippe Mathieu-Daudé]

Hi Andrey,

On 09/18/2017 04:50 PM, Andrey Smirnov wrote:
> Frame truncation length, TRUNC_FL, is determined by the contents of
> ENET_FTRL register, so convert the code to use it instead of a
> hardcoded constant.
>
> Cc: Peter Maydell <address@hidden>
> Cc: Jason Wang <address@hidden>
> Cc: address@hidden
> Cc: address@hidden
> Cc: address@hidden
> Signed-off-by: Andrey Smirnov <address@hidden>
> ---
>   hw/net/imx_fec.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/net/imx_fec.c b/hw/net/imx_fec.c
> index 767402909d..989c11be5f 100644
> --- a/hw/net/imx_fec.c
> +++ b/hw/net/imx_fec.c
> @@ -1050,8 +1050,8 @@ static ssize_t imx_enet_receive(NetClientState *nc, const 
> uint8_t *buf,
>       size += 4;
>   
>       /* Huge frames are truncted.  */
> -    if (size > ENET_MAX_FRAME_SIZE) {
> -        size = ENET_MAX_FRAME_SIZE;
> +    if (size > s->regs[ENET_FTRL]) {
> +        size = s->regs[ENET_FTRL]; >           flags |= ENET_BD_TR | 
> ENET_BD_LG;
>       }

for this to be ok you need to update imx_enet_write(), such:

     case ENET_FTRL:
-        s->regs[index] = value & 0x00003fff;
+        value &= 0x00003fff;
+        if (value > ENET_MAX_FRAME_SIZE) {
+            warn_report("%s: guest requested bigger "
+                        "frame size than QEMU supports "
+                        "(%u > %u)", value,
+                        ENET_MAX_FRAME_SIZE);
+            value = ENET_MAX_FRAME_SIZE;
+        }
+        s->regs[index] = value;
         break;

Regards,

Phil.