[prev in list] [next in list] [prev in thread] [next in thread] 

List:       freebsd-bugs
Subject:    kern/170267: IXGBE_LE32_TO_CPUS is probably an unintentional no-op
From:       Rich Lowe <richlowe () richlowe ! net>
Date:       2012-07-30 4:07:18
Message-ID: 201207300407.q6U47ICo028314 () red ! freebsd ! org
[Download RAW message or body]


> Number:         170267
> Category:       kern
> Synopsis:       IXGBE_LE32_TO_CPUS is probably an unintentional no-op
> Confidential:   no
> Severity:       non-critical
> Priority:       low
> Responsible:    freebsd-bugs
> State:          open
> Quarter:        
> Keywords:       
> Date-Required:
> Class:          sw-bug
> Submitter-Id:   current-users
> Arrival-Date:   Mon Jul 30 04:10:10 UTC 2012
> Closed-Date:
> Last-Modified:
> Originator:     Rich Lowe
> Release:        CURRENT
> Organization:
> Environment:
> Description:
Fixing a bug in another system, using an ixgbe driver derived from yours, I've \
happened upon the fact that IXGBE_LE32_TO_CPUS appears to be a no-op.

On FreeBSD, it's defined to be le32dec(), which is a pure function, however the uses \
in ixgbe_common.c are as if it were side-effecting its argument:

  3964          /* Pull in the rest of the buffer (bi is where we left off)*/
  3965          for (; bi <= dword_len; bi++) {
  3966                  buffer[bi] = IXGBE_READ_REG_ARRAY(hw, IXGBE_FLEX_MNG, bi);
  3967                  IXGBE_LE32_TO_CPUS(&buffer[bi]);
  3968          }
> How-To-Repeat:
Read through ixgbe_common.c and ixgbe_osdep.h.  I'm unsure if this causes practical \
problems (I don't have a big-endian system with this board).
> Fix:
Guessing suggests that:
    buffer[bi] = IXGBE_LE32_TO_CPUS(buffer[bi]);

(there are two instances).

Is what was intended.

> Release-Note:
> Audit-Trail:
> Unformatted:
_______________________________________________
freebsd-bugs@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-bugs
To unsubscribe, send any mail to "freebsd-bugs-unsubscribe@freebsd.org"


[prev in list] [next in list] [prev in thread] [next in thread]