Re: [PATCH] net/imx_fec: Updating the IMX_FEC IP to support loopback mode.

[Philippe Mathieu-Daudé]

On Fri, Nov 29, 2019 at 4:59 PM Wasim, Bilal <address@hidden> wrote:
>
> Thanks for the pointers philippe.. Is the patch okay to be merged without it 
> or do I need to do a re-submission with the updated username ?

If there are no review comments on your patch, I think the maintainer
taking your patch can fix this details directly, no need to resend.

> -----Original Message-----
> From: Philippe Mathieu-Daudé [mailto:address@hidden]
> Sent: Friday, November 29, 2019 8:38 PM
> To: address@hidden; address@hidden
> Cc: address@hidden; address@hidden; address@hidden; address@hidden; Wasim, 
> Bilal <address@hidden>; address@hidden; Jason Wang <address@hidden>
> Subject: Re: [PATCH] net/imx_fec: Updating the IMX_FEC IP to support loopback 
> mode.
>
> Hi Bilal,
>
> Cc'ing Jason, the maintainer of network devices.
>
> On 11/29/19 4:05 PM, address@hidden wrote:
> > From: bwasim <address@hidden>
>
> Your git setup misses your 'user.name', you could fix it running:
>
>    git config user.name "Bilal Wasim"
>
> (eventually with the --global option).
>
> The patch looks good otherwise.
>
> Thanks!
>
> > Loopback mode only works when specific conditions (as dictated by the
> > IP guide) are met, i.e. the MII_MODE is set and the RMII_MODE is
> > cleared. If not, we simply send the packet on the output queue (for TX
> > to the host network). Tested by running a custom RTOS and TXing a ton
> > of packets. The same packets were received on the RX side..
> >
> > Signed-off-by: Bilal Wasim <address@hidden>
> > ---
> >   hw/net/imx_fec.c | 27 +++++++++++++++++++++++++--
> >   1 file changed, 25 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/net/imx_fec.c b/hw/net/imx_fec.c index
> > bd99236864..c51e7f7363 100644
> > --- a/hw/net/imx_fec.c
> > +++ b/hw/net/imx_fec.c
> > @@ -256,6 +256,29 @@ static const VMStateDescription vmstate_imx_eth =
> > {
> >
> >   static void imx_eth_update(IMXFECState *s);
> >
> > +/*
> > + * Function to check if the MAC is configured to run in loopback mode.
> > + * If so, invoke the "receive" routine.
> > + * Else write to the output.
> > + * */
> > +static void send_pkt(IMXFECState *s, uint8_t *frame, int frame_size)
> > +{
> > +    NetClientState *nc = qemu_get_queue(s->nic);
> > +
> > +    /*
> > +     * Loopback or Normal mode ?
> > +     * Per the FEC Manual: If loopback is enabled, the MII_MODE
> > +     * should be SET and the RMII_MODE should be cleared. Loopback
> > +     * will only work if this criterion is met. If not met,
> > +     * we will send the frame on the output queue. */
> > +    if ((s->regs[ENET_RCR] & ENET_RCR_LOOP) && (s->regs[ENET_RCR] & 
> > ENET_RCR_MII_MODE)
> > +            && !(s->regs[ENET_RCR] & ENET_RCR_RMII_MODE)) {
> > +        nc->info->receive(nc, frame, frame_size);
> > +    } else {
> > +        qemu_send_packet(nc, frame, frame_size);
> > +    }
> > +}
> > +
> >   /*
> >    * The MII phy could raise a GPIO to the processor which in turn
> >    * could be handled as an interrpt by the OS.
> > @@ -488,7 +511,7 @@ static void imx_fec_do_tx(IMXFECState *s)
> >           frame_size += len;
> >           if (bd.flags & ENET_BD_L) {
> >               /* Last buffer in frame.  */
> > -            qemu_send_packet(qemu_get_queue(s->nic), s->frame, frame_size);
> > +            send_pkt(s, (uint8_t *)&s->frame, frame_size);
> >               ptr = s->frame;
> >               frame_size = 0;
> >               s->regs[ENET_EIR] |= ENET_INT_TXF; @@ -586,7 +609,7 @@
> > static void imx_enet_do_tx(IMXFECState *s, uint32_t index)
> >               }
> >               /* Last buffer in frame.  */
> >
> > -            qemu_send_packet(qemu_get_queue(s->nic), s->frame, frame_size);
> > +            send_pkt(s, (uint8_t *)&s->frame, frame_size);
> >               ptr = s->frame;
> >
> >               frame_size = 0;
> >
>