#1354 closed defect (fixed)

AV5282 Network driver can put empty mbuf on descriptor chain

Reported by: Frank Ueberschar Owned by: Joel Sherrill
Priority: normal Milestone: 4.10
Component: bsps Version: 4.10
Severity: normal Keywords:
Cc: frank.ueberschar@… Blocked By:
Blocking:

Description

In some cases it can occur that an empty mbuf is put on the descriptor chain. (We found it especially then when transmitting fragmented IP Pakets.)

The buffer descriptor will be filled with all the neccessary status, including the MCF5282_FEC_TxBD_R, MCF5282_FEC_TxBD_TC and MCF5282_FEC_TxBD_L and the pointer to that empty buffer. But the txBd->length will be set to 0x0.

When the last bufferdecriptor of a chain contains a zero length this will affect the DMA so the (whole ?) IP Packet beeing prepared will not be sent and the buffer descriptor and the corresponding mbuf will not be freed again.

Attachments (1)

network.c.diff (784 bytes) - added by Frank Ueberschar on Jan 12, 2009 at 12:11:39 PM.
diff of network.c (bsp: av5282)

Download all attachments as: .zip

Change History (5)

comment:1 Changed on Jan 12, 2009 at 11:03:38 AM by Frank Ueberschar

Owner: changed from Joel Sherrill to Frank Ueberschar

Changed on Jan 12, 2009 at 12:11:39 PM by Frank Ueberschar

Attachment: network.c.diff added

diff of network.c (bsp: av5282)

comment:2 Changed on Jan 12, 2009 at 12:33:23 PM by Frank Ueberschar

Owner: changed from Frank Ueberschar to Joel Sherrill

comment:3 Changed on Jan 21, 2009 at 5:12:59 PM by Joel Sherrill

Summary: AV5282 Network driverAV5282 Network driver can put empty mbuf on descriptor chain

comment:4 Changed on Jan 21, 2009 at 5:20:52 PM by Joel Sherrill

Resolution: fixed
Status: newclosed

Patch applied to 4.8 and 4.9 and CVS head

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