Re: mpc5200 fec error

[Jon Smirl <jonsmirl@gmail.com>]

On Wed, May 20, 2009 at 11:28 AM, Eric Millbrandt
<emillbrandt@dekaresearch.com> wrote:
> -----Original Message-----
> From: Jon Smirl [mailto:jonsmirl@gmail.com]
> Sent: Wednesday, May 20, 2009 11:15
> To: Eric Millbrandt
> Cc: Wolfram Sang; Grant Likely; linuxppc-dev@ozlabs.org
> Subject: Re: mpc5200 fec error
>
> On Wed, May 20, 2009 at 9:42 AM, Eric Millbrandt
> <emillbrandt@dekaresearch.com> wrote:
>>> > I am able to reproduce the error using 2.6.29.2-rt11. =A0I was able t=
o
>>> > 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
>>> >
>>> > [ =A0132.477503] net eth0: FEC_IEVENT_RFIFO_ERROR
>>> > [ =A0132.892329] net eth0: FEC_IEVENT_RFIFO_ERROR
>>> > [ =A0133.884109] net eth0: FEC_IEVENT_RFIFO_ERROR
>>> > [ =A0134.876059] 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. =A0I haven't had the
>>> chance to track it down and kill it yet. =A0I 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.
>>
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>>
>> Subject: Enable XLB pipelining for MPC5200B
>> From: Wolfram Sang <w.sang@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 fea=
ture.
>> 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@pengutronix.de>
>> Acked-by: Juergen Beisert <j.beisert@pengutronix.de>
>>
>> ---
>> =A0arch/powerpc/platforms/52xx/mpc52xx_common.c | =A0 =A07 +++++++
>> =A01 file changed, 7 insertions(+)
>>
>> Index: arch/powerpc/platforms/52xx/mpc52xx_common.c
>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> --- arch/powerpc/platforms/52xx/mpc52xx_common.c.orig
>> +++ arch/powerpc/platforms/52xx/mpc52xx_common.c
>> @@ -107,6 +107,13 @@ mpc5200_setup_xlb_arbiter(void)
>> =A0 =A0 =A0 =A0 */
>> =A0 =A0 =A0 =A0if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) =3D=3D MPC5200_S=
VR)
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0out_be32(&xlb->config, in_be32(&xlb->conf=
ig) | MPC52xx_XLB_CFG_PLDIS);
>> +#if 0
>> + =A0 =A0 =A0 /*
>> + =A0 =A0 =A0 =A0* Enable pipelining, fixes FEC problems. The previous w=
orkaround is not
>> + =A0 =A0 =A0 =A0* needed, as we have an MPC5200B (not A).
>> + =A0 =A0 =A0 =A0*/
>> + =A0 =A0 =A0 out_be32(&xlb->config, in_be32(&xlb->config) & ~MPC52xx_XL=
B_CFG_PLDIS);
>> +#endif
>>
>> =A0 =A0 =A0 =A0iounmap(xlb);
>> =A0}
>>
>> --
>> Pengutronix e.K. =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | W=
olfram Sang =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0|
>> Industrial Linux Solutions =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | http://www.=
pengutronix.de/ =A0|
>>
>> Wolfram,
>>
>> Thanks, but no luck with this patch. =A0It was already setup correctly b=
y 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) |=3D (1 << 13=
);
> cpu/mpc5xxx/cpu_init.c: *(vu_long *)(MPC5XXX_XLBARB + 0x40) |=3D (1 << 15=
);
>
>
> --
> Jon Smirl
> jonsmirl@gmail.com
>
> If you look a few more lines down you should see
> # if defined(CFG_XLB_PIPELINING)
> =A0 =A0 =A0 =A0/* Enable piplining */
> =A0 =A0 =A0 =A0*(vu_long *)(MPC5XXX_XLBARB + 0x40) &=3D ~(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.

--=20
Jon Smirl
jonsmirl@gmail.com