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From: Thierry Reding <treding@nvidia•com>
To: Joao Pinto <Joao.Pinto@synopsys•com>
Cc: <davem@davemloft•net>, <clabbe.montjoie@gmail•com>,
	<niklas.cassel@axis•com>, <netdev@vger•kernel.org>
Subject: Re: [PATCH 2/4] net: stmmac: adding multiple buffers for rx
Date: Tue, 4 Apr 2017 21:14:53 +0200	[thread overview]
Message-ID: <20170404191453.GB24271@ulmo.ba.sec> (raw)
In-Reply-To: <4f35e9a73521ba4ab4868c75950166fb757b5f8a.1491328304.git.jpinto@synopsys.com>

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On Tue, Apr 04, 2017 at 06:54:25PM +0100, Joao Pinto wrote:
[...]
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
[...]
>  static void stmmac_display_rx_rings(struct stmmac_priv *priv)
>  {
> +	u32 rx_cnt = priv->plat->rx_queues_to_use;
>  	void *head_rx;
> +	u32 queue;
>  
> -	if (priv->extend_desc)
> -		head_rx = (void *)priv->dma_erx;
> -	else
> -		head_rx = (void *)priv->dma_rx;
> +	/* Display RX rings */
> +	for (queue = 0; queue < rx_cnt; queue++) {
> +		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
>  
> -	/* Display RX ring */
> -	priv->hw->desc->display_ring(head_rx, DMA_RX_SIZE, true);
> +		pr_info("\tRX Queue %d rings\n", queue);

Nit: %u is the right specifier for unsigned integers.

> @@ -1107,46 +1135,65 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
[...]
>  err_init_rx_buffers:
> -	while (--i >= 0)
> -		stmmac_free_rx_buffers(priv, i);
> +	while (queue-- >= 0) {

Why are you switching to postfix decrement here? Not only is it
inconsistent with the prefix decrement below, I think this also gives
you a wrong result. Consider what happens if queue == 0. The condition
evaluates to true, but within the loop the queue variable will wrap to
~0 and probably crash stmmac_free_rx_buffers().

Other than that, this looks fine, so with the above fixed:

Reviewed-by: Thierry Reding <treding@nvidia•com>

Also works on Tegra186, so:

Tested-by: Thierry Reding <treding@nvidia•com>

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  reply	other threads:[~2017-04-04 19:15 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-04 17:54 [PATCH 0/4 net-next] net: stmmac: adding multiple buffers Joao Pinto
2017-04-04 17:54 ` [PATCH 1/4] net: stmmac: break some functions into RX and TX scopes Joao Pinto
2017-04-04 17:54   ` [PATCH 2/4] net: stmmac: adding multiple buffers for rx Joao Pinto
2017-04-04 19:14     ` Thierry Reding [this message]
2017-04-04 19:15     ` Thierry Reding
2017-04-04 19:23     ` Thierry Reding
2017-04-04 17:54   ` [PATCH 3/4] net: stmmac: adding multiple buffers for TX Joao Pinto
2017-04-04 19:19     ` Thierry Reding
2017-04-04 17:54   ` [PATCH 4/4] net: stmmac: adding multiple napi mechanism Joao Pinto
2017-04-04 19:28     ` Thierry Reding
2017-04-04 18:57   ` [PATCH 1/4] net: stmmac: break some functions into RX and TX scopes Thierry Reding
2017-04-05  9:04     ` Joao Pinto

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