[PATCH] net: smc1111: fix memory congestions

[Sascha Hauer]

On Thu, Jan 01, 2015 at 09:04:22PM +0100, Robert Jarzmik wrote:
> As the SMC1111 has a shared pool of 2k memory buckets for both
> transmission and reception, and as there are variants which have as few
> as 4 buckets in total, the memory pool can be hogged by unclaimed
> receptions, and impeed any further transmission.
> 
> This happens on the zylonite pxa board, where 4 packets, most probably
> icmp and arp, fill the 4 buckets, preventing any further ethernet
> transmission, and stalling the driver.
> 
> The fix is rather rough : whenever all the buckets are filled by
> reception packets, and if a transmission is required, the transmission
> code path will empty up all received packets.

I don't know the hardware (not anymore, fortunately ;), but isn't it
possible to dedicate one bucket for transmitting only, so that it will
never be occupied by a received packet?

Sascha

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