[U-Boot] [PATCH] net: macb: Fix rx buffer cache handling

[Bin Meng]

On Fri, Aug 23, 2019 at 5:17 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Stefan,
>
> On Fri, Aug 23, 2019 at 5:02 PM Stefan Roese <sr at denx.de> wrote:
> >
> > With commit c6d07bf440bc ("net/macb: increase RX buffer size for GEM")
> > ethernet support does not work any more with d-cache enabled on the
> > AT91SAM. The reason is, that MACB_RX_BUFFER_SIZE was changed from 4096
> > to 128 but this change was not refected in the rx_buffer flush and
> > invalidate functions, as these also use this macro.
> >
> > This patch now fixes this by calculating the rx buffer size correctly
> > again in those functions. With this change, ethernet works again
> > reliably on my AT91SAM board.
> >
> > Signed-off-by: Stefan Roese <sr at denx.de>
> > Cc: Ramon Fried <rfried.dev at gmail.com>
> > Cc: Eugen Hristev <eugen.hristev at microchip.com>
> > Cc: Anup Patel <anup.patel at wdc.com>
> > Cc: Bin Meng <bmeng.cn at gmail.com>
> > Cc: Joe Hershberger <joe.hershberger at ni.com>
> > ---
> >  drivers/net/macb.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> > index c99cf663a4..fca380d012 100644
> > --- a/drivers/net/macb.c
> > +++ b/drivers/net/macb.c
> > @@ -296,13 +296,15 @@ static inline void macb_flush_ring_desc(struct macb_device *macb, bool rx)
> >  static inline void macb_flush_rx_buffer(struct macb_device *macb)
> >  {
> >         flush_dcache_range(macb->rx_buffer_dma, macb->rx_buffer_dma +
> > -                          ALIGN(MACB_RX_BUFFER_SIZE, PKTALIGN));
> > +                          ALIGN(MACB_RX_BUFFER_SIZE * MACB_RX_RING_SIZE,
> > +                                PKTALIGN));
>
> This looks wrong to me.
>
> Shouldn't it be:
>
>          flush_dcache_range(macb->rx_buffer_dma, macb->rx_buffer_dma +
>                           ALIGN(macb->rx_buffer_size, PKTALIGN));

Ah, for MACB, looks it should be "MACB_RX_BUFFER_SIZE *
MACB_RX_RING_SIZE", but for GEM, I am not sure.

Should it be:

          flush_dcache_range(macb->rx_buffer_dma, macb->rx_buffer_dma +
                           ALIGN(macb->rx_buffer_size *
MACB_RX_RING_SIZE, PKTALIGN));

>
> >  }
> >
> >  static inline void macb_invalidate_rx_buffer(struct macb_device *macb)
> >  {
> >         invalidate_dcache_range(macb->rx_buffer_dma, macb->rx_buffer_dma +
> > -                               ALIGN(MACB_RX_BUFFER_SIZE, PKTALIGN));
> > +                               ALIGN(MACB_RX_BUFFER_SIZE * MACB_RX_RING_SIZE,
> > +                                     PKTALIGN));
> >  }
> >
> >  #if defined(CONFIG_CMD_NET)
> > --

Regards,
Bin