mpc5200 fec error
Eric Millbrandt
emillbrandt at dekaresearch.com
Thu May 21 02:41:38 EST 2009
> On Wed, May 20, 2009 at 9:42 AM, Eric Millbrandt
> <emillbrandt at dekaresearch.com> wrote:
>>> > I am able to reproduce the error using 2.6.29.2-rt11. I was able to
>>> > mitigate the problem by raising the priority of the transmit irq.
>>> > However when running an NFS server on the pcm030 under high cpu load I
>>> > now get
>>> >
>>> > [ 132.477503] net eth0: FEC_IEVENT_RFIFO_ERROR
>>> > [ 132.892329] net eth0: FEC_IEVENT_RFIFO_ERROR
>>> > [ 133.884109] net eth0: FEC_IEVENT_RFIFO_ERROR
>>> > [ 134.876059] net eth0: FEC_IEVENT_RFIFO_ERROR
>>> >
>>> > Raising the priority of the rx irq does not seem to fix this problem
>>> > though.
>>>
>>> Hi Eric,
>>>
>>> This error has been seen before in non-rt kernels. I haven't had the
>>> chance to track it down and kill it yet. I believe there are locking
>>> issues associated with it.
>>
>> Uuuh, I recall this message. Kept me busy for some time :(
>>
>> You might try this patch which helped in our situation.
>>
>> ===========
>>
>> Subject: Enable XLB pipelining for MPC5200B
>> From: Wolfram Sang <w.sang at pengutronix.de>
>>
>> Enable pipelining as it helps getting rid of FEC problems.
>> Not intended for upstream, this must be dealt differently there.
>>
>> This patch is disabled by default. The bootloader should enable this feature.
>> So, this patch is only intended to be used where the bootloader does it in a
>> wrong manner and can't be replaced.
>>
>> Signed-off-by: Wolfram Sang <w.sang at pengutronix.de>
>> Acked-by: Juergen Beisert <j.beisert at pengutronix.de>
>>
>> ---
>> arch/powerpc/platforms/52xx/mpc52xx_common.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> Index: arch/powerpc/platforms/52xx/mpc52xx_common.c
>> ===================================================================
>> --- arch/powerpc/platforms/52xx/mpc52xx_common.c.orig
>> +++ arch/powerpc/platforms/52xx/mpc52xx_common.c
>> @@ -107,6 +107,13 @@ mpc5200_setup_xlb_arbiter(void)
>> */
>> if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR)
>> out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
>> +#if 0
>> + /*
>> + * Enable pipelining, fixes FEC problems. The previous workaround is not
>> + * needed, as we have an MPC5200B (not A).
>> + */
>> + out_be32(&xlb->config, in_be32(&xlb->config) & ~MPC52xx_XLB_CFG_PLDIS);
>> +#endif
>>
>> iounmap(xlb);
>> }
>>
>> --
>> Pengutronix e.K. | Wolfram Sang |
>> Industrial Linux Solutions | http://www.pengutronix.de/ |
>>
>> Wolfram,
>>
>> Thanks, but no luck with this patch. It was already setup correctly by U-Boot.
>
>
> I don't see where this gets enabled in the u-boot source. Have you
> added it locally?
>
> These are the only two I see:
> cpu/mpc5xxx/cpu_init.c: *(vu_long *)(MPC5XXX_XLBARB + 0x40) |= (1 << 13);
> cpu/mpc5xxx/cpu_init.c: *(vu_long *)(MPC5XXX_XLBARB + 0x40) |= (1 << 15);
>
>
> --
> Jon Smirl
> jonsmirl at gmail.com
>
> If you look a few more lines down you should see
> # if defined(CFG_XLB_PIPELINING)
> /* Enable piplining */
> *(vu_long *)(MPC5XXX_XLBARB + 0x40) &= ~(1 << 31);
> # endif
>
> I obtained the u-boot sources directly from phytec, for my phyCore, so I am not sure if they added it.
It is ok in main u-boot source. I just missed the lower section.
--
Jon Smirl
jonsmirl at gmail.com
It looks like the phy is never getting reset properly after the FEC_IEVENT_RFIFO_ERROR. I threw some printk's into the fec mdio driver
/drivers/net/fec_mpc52xx_phy.c
25 static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
26 int reg, u32 value)
27 {
28 struct mpc52xx_fec_mdio_priv *priv = bus->priv;
29 struct mpc52xx_fec __iomem *fec;
30 int tries = 100;
31
32 value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
33 value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;
34
35 fec = priv->regs;
36 out_be32(&fec->ievent, FEC_IEVENT_MII);
37 out_be32(&priv->regs->mii_data, value);
38
39 /* wait for it to finish, this takes about 23 us on lite5200b */
40 while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
41 udelay(5);
42
43 if (!tries) {
44 printk("Unable to reset phy\n");
45 return -ETIMEDOUT;
46 }
47
48 return value & FEC_MII_DATA_OP_RD ?
49 in_be32(&priv->regs->mii_data) & FEC_MII_DATA_DATAMSK : 0;
50 }
and got this
[ 127.085632] net eth0: FEC_IEVENT_RFIFO_ERROR
[ 127.093401] Resetting FEC
[ 127.096620] Unable to reset phy
[ 127.322224] Unable to reset phy
[ 128.321987] PHY: f0003000:00 - Link is Down
[ 129.221034] net eth0: FEC_IEVENT_RFIFO_ERROR
[ 129.228165] Resetting FEC
[ 129.231384] Unable to reset phy
[ 129.322286] Unable to reset phy
[ 132.885863] net eth0: FEC_IEVENT_RFIFO_ERROR
[ 132.893002] Resetting FEC
[ 132.896176] Unable to reset phy
[ 133.322202] Unable to reset phy
[ 135.684793] net eth0: FEC_IEVENT_RFIFO_ERROR
[ 135.691969] Resetting FEC
[ 135.695192] Unable to reset phy
[ 136.322530] Unable to reset phy
[ 138.490805] net eth0: FEC_IEVENT_RFIFO_ERROR
[ 138.497963] Resetting FEC
[ 138.501135] Unable to reset phy
[ 139.334200] Unable to reset phy
I guess I have to spend some quality time with the 5200 manual.
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