svn commit: r293928 - stable/10/sys/dev/sfxge

[Andrew Rybchenko]

Author: arybchik
Date: Thu Jan 14 14:17:05 2016
New Revision: 293928
URL: https://svnweb.freebsd.org/changeset/base/293928

Log:
  MFC r291488
  
  sfxge: avoid TSO packets collapses bacause of not 2K aligned data
  
  Sponsored by:   Solarflare Communications, Inc.

Modified:
  stable/10/sys/dev/sfxge/sfxge_tx.h
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/sfxge/sfxge_tx.h
==============================================================================
--- stable/10/sys/dev/sfxge/sfxge_tx.h	Thu Jan 14 14:16:26 2016	(r293927)
+++ stable/10/sys/dev/sfxge/sfxge_tx.h	Thu Jan 14 14:17:05 2016	(r293928)
@@ -51,11 +51,13 @@
 
 /* Maximum number of DMA segments needed to map an mbuf chain.  With
  * TSO, the mbuf length may be just over 64K, divided into 2K mbuf
- * clusters.  (The chain could be longer than this initially, but can
- * be shortened with m_collapse().)
+ * clusters taking into account that the first may be not 2K cluster
+ * boundary aligned.
+ * The chain could be longer than this initially, but can be shortened
+ * with m_collapse().
  */
 #define	SFXGE_TX_MAPPING_MAX_SEG					\
-	(1 + howmany(SFXGE_TSO_MAX_SIZE, MCLBYTES))
+	(1 + howmany(SFXGE_TSO_MAX_SIZE, MCLBYTES) + 1)
 
 /*
  * Buffer mapping flags.