[PATCH 1/6] net: macb: use dummy descriptor for RBQP

[Padmarao.Begari at microchip.com]

Hi Eugen,

This series of patches break my side of work(patches) so you need to create patches after my patches are going into master branch because my patches are already reviewed and tested.

Regards
Padmarao
________________________________
From: Eugen Hristev - M18282 <Eugen.Hristev at microchip.com>
Sent: Wednesday, December 16, 2020 12:24 PM
To: anup.patel at wdc.com <anup.patel at wdc.com>; bin.meng at windriver.com <bin.meng at windriver.com>; Padmarao Begari - I30397 <Padmarao.Begari at microchip.com>
Cc: Claudiu Beznea - M18063 <Claudiu.Beznea at microchip.com>; joe.hershberger at ni.com <joe.hershberger at ni.com>; u-boot at lists.denx.de <u-boot at lists.denx.de>
Subject: Re: [PATCH 1/6] net: macb: use dummy descriptor for RBQP

On 03.12.2020 11:25, Claudiu Beznea wrote:
> In case of multiple queues on RX side the queue scheduler
> will try to use all the available configured queues (with
> descriptors having TX_USED bit cleared). If at least one RBQP
> points to a descriptor with a valid used bit configuration then
> the reception may block as this may point to any memory. To avoid
> this scenario all the queues (except queue zero) were disabled by
> setting DMA descriptors with used bit set on proper RBQP. The driver
> anyway uses only queue 0 for TX/RX.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea at microchip.com>
> ---

Hi Anup, Bin, Padmarao,

I noticed on the mailing list that you have been actively working and
testing the Macb driver on various platforms, we have this series
outstanding and I want to make sure that it does not break anything on
your side, so it would be appreciated if you could have a look or test
it before it goes into master branch.

Thanks !
Eugen


>   drivers/net/macb.c | 4 +++-
>   drivers/net/macb.h | 2 ++
>   2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> index b80a259ff757..836eb85ec96a 100644
> --- a/drivers/net/macb.c
> +++ b/drivers/net/macb.c
> @@ -732,8 +732,10 @@ static int gmac_init_multi_queues(struct macb_device *macb)
>        flush_dcache_range(macb->dummy_desc_dma, macb->dummy_desc_dma +
>                        ALIGN(MACB_TX_DUMMY_DMA_DESC_SIZE, PKTALIGN));
>
> -     for (i = 1; i < num_queues; i++)
> +     for (i = 1; i < num_queues; i++) {
>                gem_writel_queue_TBQP(macb, macb->dummy_desc_dma, i - 1);
> +             gem_writel_queue_RBQP(macb, macb->dummy_desc_dma, i - 1);
> +     }
>
>        return 0;
>   }
> diff --git a/drivers/net/macb.h b/drivers/net/macb.h
> index 9b16383eba46..28c7fe306883 100644
> --- a/drivers/net/macb.h
> +++ b/drivers/net/macb.h
> @@ -768,5 +768,7 @@
>   #define GEM_RX_CSUM_CHECKED_MASK            2
>   #define gem_writel_queue_TBQP(port, value, queue_num)       \
>        writel((value), (port)->regs + GEM_TBQP(queue_num))
> +#define gem_writel_queue_RBQP(port, value, queue_num)        \
> +     writel((value), (port)->regs + GEM_RBQP(queue_num))
>
>   #endif /* __DRIVERS_MACB_H__ */
>