MPC5200B FEC_IEVENT_RFIFO_ERROR leading to Link is Down

[Roman Fietze]

Hello,

When having high traffic on the MPC5200B ATA (MWDMA2), FEC (100MBit)
and LPC (MTD FLASH read) I will get the typical
FEC_IEVENT_RFIFO_ERROR's.

Without the FLASH reads, that we use to stress the probably existing
LPC arbiter or MPC5200B silicon bug when running UDMA2+LPC, and which
should not happen using MWDMA2+LPC, I could not yet reproduce the
FEC_IEVENT_RFIFO_ERROR.

Now comes the problem: since the PHY driver rework followed by John
Bonesio's fix (rev 37ccd92f55c6c6) to avoid accessing the DIO bus at
interrupt context, this now sometimes causes an irrecoverable link
down (PHY: f0003000:00 - Link is Down). This patch is of course
necessary to avoid a panic.

I can reproduce that on the current DENX/master using an own board
very close to the Lite5200B. This board runs fine under the old
2.4.25, of course also sometimes showing the FEC FIFO error.

Any ideas?


Roman

-- 
Roman Fietze                Telemotive AG Büro Mühlhausen
Breitwiesen                              73347 Mühlhausen
Tel.: +49(0)7335/18493-45        http://www.telemotive.de