Oops: 17 SMP ARM (v3.16-rc2)

[Russell King - ARM Linux]

On Thu, Aug 07, 2014 at 11:11:06AM +0000, Mattis Lorentzon wrote:
> Russell,
> 
> > Can you ascertain whether these stalls are a result of some failure of the
> > receive side or the transmit side - you should be able to tell that if you watch
> > the packet counts via ifconfig on the stalled card.  Also, it would be useful to
> > know whether the FEC interrupt was firing.
> 
> grep eth /proc/interrupts
> 151:          0          0          0          0       GIC 151  2188000.ethernet
> 166:    1205661          0          0          0  gpio-mxc   6  2188000.ethernet
> 
> The interrupt counter 166 increases regularly during the stalls.
> Ifconfig indicates that the RX and TX  counters do not increase.

Hmm, I'm slightly confused.  On my iMX6Q, I have:

150:     581754          0          0          0       GIC 150  2188000.ethernet
151:          0          0          0          0       GIC 151  2188000.ethernet

In the DT file, we have:

                        fec: ethernet at 02188000 {
                                compatible = "fsl,imx6q-fec";
                                reg = <0x02188000 0x4000>;
                                interrupts-extended =
                                        <&intc 0 118 IRQ_TYPE_LEVEL_HIGH>,
                                        <&intc 0 119 IRQ_TYPE_LEVEL_HIGH>;
                                clocks = <&clks 117>, <&clks 117>, <&clks 190>;
                                clock-names = "ipg", "ahb", "ptp";
                                status = "disabled";
                        };

which, for the gic, would be 118 + 32 (first SPI) = 150, 119 + 32 = 151.
Yet you seem to have nothing registered against GIC 150, instead having
an interrupt against GPIO 6.

This seems very odd, and as this is an on-SoC device, I don't see why
you would want to bind the interrupts for the FEC device any differently
to standard platforms.

This could well be the cause of your stalls.

What's GPIO 6 used for on your board?

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