Re: [PATCH] net/macb: increase RX buffer size for GEM

From: David Miller
Date: Tue Dec 04 2012 - 13:22:25 EST

From: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
Date: Mon, 3 Dec 2012 13:15:43 +0100

> Macb Ethernet controller requires a RX buffer of 128 bytes. It is
> highly sub-optimal for Gigabit-capable GEM that is able to use
> a bigger DMA buffer. Change this constant and associated macros
> with data stored in the private structure.
> I also kept the result of buffers per page calculation to lower the
> impact of this move to a variable rx buffer size on rx hot path.
> RX DMA buffer size has to be multiple of 64 bytes as indicated in
> DMA Configuration Register specification.
> Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

This looks like it will waste a couple hundred bytes for 1500 MTU
frames, am I right?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at