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

[Ramon Fried]

On Fri, Aug 23, 2019 at 12:22 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> 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));
>
Good catch !, I'll issue a fix soon.
Thanks,
Ramon
> >
> > >  }
> > >
> > >  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