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<DIV><FONT face=Arial size=2>Hi all,<BR>on my MPC8321E with linux-2.6.36 I get
this netdev watchdog warning "NETDEV WATCHDOG: eth0 (of:ucc_geth): transmit
queue 0 timed out" if the link mode is half-duplex.<BR>The warning is caused,
because all Tx BDs are full and packet transmission is stopped with
netif_stop_queue() in ucc_geth_start_xmit().</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>You can reproduce the bug in the following
way:<BR>- Connect to a switch, that supports only 10baseT, or set the mode
manually with "mii-diag -F 10baseT".<BR>- Open a telnet session to the target.
Generate higher traffic with executing maybe "cat /proc/interrupts" many
times.<BR>- After some tries the ethernet connection will be down<SPAN
class=812521913-23112010>,</SPAN> then again after approx. 30s seconds the
netdev watchdog will dump the warning.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>It is unclear to me why the TxBDs get full. Due to
missing "Tx buffer sent" interrupts, it seems that the QE stops the
transmission.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I found some issue in the errata: "QE_ENET20: UEC
may stop transmitting after late collision". But UCCE[TXE] is never set in this
case.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT><FONT face=Arial><FONT size=2><SPAN class=812521913-23112010>Thank
you for your help in advance and best regards</SPAN>,</FONT></FONT></FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2><FONT face=Arial>Andreas Schmitz<BR></FONT><FONT
face=Arial><FONT size=1>Software
Engineer<BR></FONT>_______________________________________
<BR><STRONG>RIEDEL<BR></STRONG>Communications GmbH & Co. KG<BR>Uellendahler
Str. 353<BR>42109 Wuppertal<BR>Germany </FONT></FONT></DIV>
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