Re: [PATCH v2] net/macb: fix ISR clear-on-write behavior only for some SoC

[Jean-Christophe PLAGNIOL-VILLARD]

On 15:00 Tue 14 May     , Nicolas Ferre wrote:
> Commit 749a2b6 (net/macb: clear tx/rx completion flags in ISR)
> introduces clear-on-write on ISR register. This behavior is not always
> implemented when using Cadence MACB/GEM and is breaking other platforms.
> We are using the Design Configuration Register 1 information and a capability
> property to actually activate this clear-on-write behavior on ISR.
> 
> Reported-by: Hein Tibosch <hein_tibo...@yahoo.es>
> Signed-off-by: Nicolas Ferre <nicolas.fe...@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagn...@jcrosoft.com>
> ---
> v2: - use DCFG1 bit 23 integration information instead of device tree
>       compatibility string to retreive information about c-o-r vs. c-o-w ISR.
>     - move configuration in macb_init_hw() function instead of probe() - at
>       "open" time.
> 
> As I have changed the most of this patch, I will collect your Ack and feedback
> just like a new patch. Thanks for your help...
> 
> Bye,
> 
>  drivers/net/ethernet/cadence/macb.c | 18 ++++++++++++++++--
>  drivers/net/ethernet/cadence/macb.h |  7 +++++++
>  2 files changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cadence/macb.c 
> b/drivers/net/ethernet/cadence/macb.c
> index 6be513d..c89aa41 100644
> --- a/drivers/net/ethernet/cadence/macb.c
> +++ b/drivers/net/ethernet/cadence/macb.c
> @@ -485,7 +485,8 @@ static void macb_tx_interrupt(struct macb *bp)
>       status = macb_readl(bp, TSR);
>       macb_writel(bp, TSR, status);
>  
> -     macb_writel(bp, ISR, MACB_BIT(TCOMP));
> +     if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
> +             macb_writel(bp, ISR, MACB_BIT(TCOMP));
>  
>       netdev_vdbg(bp->dev, "macb_tx_interrupt status = 0x%03lx\n",
>               (unsigned long)status);
> @@ -738,7 +739,8 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
>                        * now.
>                        */
>                       macb_writel(bp, IDR, MACB_RX_INT_FLAGS);
> -                     macb_writel(bp, ISR, MACB_BIT(RCOMP));
> +                     if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
> +                             macb_writel(bp, ISR, MACB_BIT(RCOMP));
>  
>                       if (napi_schedule_prep(&bp->napi)) {
>                               netdev_vdbg(bp->dev, "scheduling RX softirq\n");
> @@ -1062,6 +1064,17 @@ static void macb_configure_dma(struct macb *bp)
>       }
>  }
>  
> +/*
> + * Configure peripheral capacities according to integration options used
> + */
> +static void macb_configure_caps(struct macb *bp)
> +{
> +     if (macb_is_gem(bp)) {
> +             if (GEM_BF(IRQCOR, gem_readl(bp, DCFG1)) == 0)
> +                     bp->caps |= MACB_CAPS_ISR_CLEAR_ON_WRITE;
> +     }
> +}
> +
>  static void macb_init_hw(struct macb *bp)
>  {
>       u32 config;
> @@ -1084,6 +1097,7 @@ static void macb_init_hw(struct macb *bp)
>       bp->duplex = DUPLEX_HALF;
>  
>       macb_configure_dma(bp);
> +     macb_configure_caps(bp);
>  
>       /* Initialize TX and RX buffers */
>       macb_writel(bp, RBQP, bp->rx_ring_dma);
> diff --git a/drivers/net/ethernet/cadence/macb.h 
> b/drivers/net/ethernet/cadence/macb.h
> index 993d703..548c0ec 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/drivers/net/ethernet/cadence/macb.h
> @@ -300,6 +300,8 @@
>  #define MACB_REV_SIZE                                16
>  
>  /* Bitfields in DCFG1. */
> +#define GEM_IRQCOR_OFFSET                    23
> +#define GEM_IRQCOR_SIZE                              1
>  #define GEM_DBWDEF_OFFSET                    25
>  #define GEM_DBWDEF_SIZE                              3
>  
> @@ -323,6 +325,9 @@
>  #define MACB_MAN_READ                                2
>  #define MACB_MAN_CODE                                2
>  
> +/* Capability mask bits */
> +#define MACB_CAPS_ISR_CLEAR_ON_WRITE         0x1
> +
>  /* Bit manipulation macros */
>  #define MACB_BIT(name)                                       \
>       (1 << MACB_##name##_OFFSET)
> @@ -574,6 +579,8 @@ struct macb {
>       unsigned int            speed;
>       unsigned int            duplex;
>  
> +     u32                     caps;
> +
>       phy_interface_t         phy_interface;
>  
>       /* AT91RM9200 transmit */
> -- 
> 1.8.0
> 
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