[BUG]: imx6q (wandboard): Very unstable ethernet since kernel 3.16

[Russell King - ARM Linux]

On Fri, Aug 08, 2014 at 03:15:58PM +0200, Thomas Scheiblauer wrote:
> Since Kernel 3.16 (running on 3.16.0) the ethernet (fec) connection
> stops working after exchanging very little data. Sometimes it comes back
> again for some seconds and drops again. No clues in dmesg.
> 
> After increasing TX_RING_SIZE in "drivers/net/ethernet/freescale/fec.h"
> from 512 to 1024 the connection seems to stay stable (judging after
> about half an hour of testing) but I really don't have experience with
> kernel driver hacking, so I'm not sure what I'm doing here.

Interesting.  There have been some other reports of instability in a
similar manner to that which you report, and, like the wanboard, they
too have this:

        interrupts-extended = <&gpio1 6 IRQ_TYPE_LEVEL_HIGH>,
                              <&intc 0 119 IRQ_TYPE_LEVEL_HIGH>;

Could it be that gpio1 6 doesn't actually work very well?  What happens
if you comment out the above property in
arch/arm/boot/dts/imx6qdl-wandboard.dtsi so you're using the standard
interrupt on GIC 150?

-- 
FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up
according to speedtest.net.