From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Warren <swarren@wwwdotorg.org>
Date: Wed, 20 Aug 2014 13:33:06 -0600
Subject: [U-Boot] [PATCH 8/9] net: rtl8169: Use non-cached memory if
	available
In-Reply-To: <1408348852-30894-9-git-send-email-thierry.reding@gmail.com>
References: <1408348852-30894-1-git-send-email-thierry.reding@gmail.com>
	<1408348852-30894-9-git-send-email-thierry.reding@gmail.com>
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On 08/18/2014 02:00 AM, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> To work around potential issues with explicit cache maintenance of the
> RX and TX descriptor rings, allocate them from a pool of uncached memory
> if the architecture supports it.

> diff --git a/drivers/net/rtl8169.c b/drivers/net/rtl8169.c

> +#ifndef CONFIG_SYS_NONCACHED_MEMORY
>   /* Define the TX Descriptor */
>   DEFINE_ALIGN_BUFFER(struct TxDesc, tx_ring, NUM_TX_DESC, RTL8169_ALIGN);
>
>   /* Define the RX Descriptor */
>   DEFINE_ALIGN_BUFFER(struct RxDesc, rx_ring, NUM_RX_DESC, RTL8169_ALIGN);
> +#endif

It feels slightly inconsistent to have one case allocate this memory in 
BSS at compile-time, and in the other to allocate it dynamically.

Would it be better to remove this global, and simply call different APIs 
(regular aligned malloc, v.s. non-cached allocate) during rtl_init()?