[U-Boot-Users] MPC8xx-board: just 10MBit transfer rate

Dear u-boot users,
i got u-boot 1.1.3 and linux 2.4.25 running on my custom MPC875-board. But the ethernet-connection (FEC-Controller) seems to be abit slow. The MII-transceiver chip autonegotiates a speed of 100MBit but when downloading files via tftp/ftp in u-boot or linux the transfer seems to happen in 10MBit mode.
Could this be caused by the low system clock (40MHz) ? What else ?
Best regards, Josef

On Tuesday 14 March 2006 17:37, Josef Angermeier wrote:
Dear u-boot users,
i got u-boot 1.1.3 and linux 2.4.25 running on my custom MPC875-board. But the ethernet-connection (FEC-Controller) seems to be abit slow. The MII-transceiver chip autonegotiates a speed of 100MBit but when downloading files via tftp/ftp in u-boot or linux the transfer seems to happen in 10MBit mode.
Could this be caused by the low system clock (40MHz) ? What else ?
Best regards, Josef
TFTP is not a speed demon. This is a protocol issue. Has nothing to do with the ethernet negotiated rate.
Pantelis

Josef Angermeier wrote:
Dear u-boot users,
i got u-boot 1.1.3 and linux 2.4.25 running on my custom MPC875-board. But the ethernet-connection (FEC-Controller) seems to be abit slow. The MII-transceiver chip autonegotiates a speed of 100MBit but when downloading files via tftp/ftp in u-boot or linux the transfer seems to happen in 10MBit mode.
Could this be caused by the low system clock (40MHz) ? What else ?
Best regards, Josef
Crank up ethereal and see what packets are being transmitted, received, and the time between packets. I suspect you will see either gross delays or retransmissions (and quite possibly both), indicating packet handling problems of some form or another. (Unreasonable to speculate what, without seeing the ethereal dump. Once you see the packet pattern, the problem usually is fairly obvious.)
If not, you need to recalibrate your expectations. :-) TFTP is a transmit-acknowledgment protocol with no pipelining, so packet n+1 doesn't get transmitted until packet n is acknowledged. If the <ack> is slow, your transfer rate will be slow also.
gvb
participants (3)
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Jerry Van Baren
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Josef Angermeier
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Pantelis Antoniou