Re: tg3 driver upgrade (Linux 2.6.32 -> 3.2) breaks IBM Bladecenter SoL

"Michael Chan" [off-list ref] writes:

On Fri, 2012-09-28 at 22:45 +0200, Ferenc Wagner wrote: 

quoted

Upgrading the kernel on our HS20 blades resulted in their SoL (serial
over LAN) connection being broken.  The disconnection happens when eth0
(the interface involved in SoL) is brought up during the boot sequence.
If I later "ip link set eth0 down", then the connection is restored, but
"ip link set eth0 up" breaks it again on 3.2.  ethtool -a, -c, -g, -k
and -u show no difference; ethtool -i on the 2.6.32 kernel reports:

driver: tg3
version: 3.116
firmware-version: 5704s-v3.38, ASFIPMIs v2.47
bus-info: 0000:05:01.0

In the 3.2 kernel the driver version is 3.121.

2.6.32 to 3.2 is a big jump.  Can you narrow this down further?  It will
be hard for us to find a HS20 with 5704 to test this.  Thanks.

I'm done with bisecting it: the first bad commit is:

commit dabc5c670d3f86d15ee4f42ab38ec5bd2682487d
Author: Matt Carlson [off-list ref]
Date:   Thu May 19 12:12:52 2011 +0000

    tg3: Move TSO_CAPABLE assignment
    
    This patch moves the code that asserts the TSO_CAPABLE flag closer to
    where the TSO capabilities flags are set.  There isn't a good enough
    reason for the code to be separated.
    
    Signed-off-by: Matt Carlson [off-list ref]
    Reviewed-by: Michael Chan [off-list ref]
    Signed-off-by: David S. Miller [off-list ref]

On the other hand, losing the SoL console even temporarily during boot
(as it happens with a minimal kernel before this commit) isn't nice
either.  I'll try to look after that, too, just mentioning it here...
-- 
Regards,
Feri.

On Tue, 2012-10-02 at 14:07 +0200, Ferenc Wagner wrote:

I'm done with bisecting it: the first bad commit is:

commit dabc5c670d3f86d15ee4f42ab38ec5bd2682487d
Author: Matt Carlson [off-list ref]
Date:   Thu May 19 12:12:52 2011 +0000

    tg3: Move TSO_CAPABLE assignment
    
    This patch moves the code that asserts the TSO_CAPABLE flag closer
to
    where the TSO capabilities flags are set.  There isn't a good
enough
    reason for the code to be separated.
    
    Signed-off-by: Matt Carlson [off-list ref]
    Reviewed-by: Michael Chan [off-list ref]
    Signed-off-by: David S. Miller [off-list ref]

Thanks, I'll look into this.

On the other hand, losing the SoL console even temporarily during boot
(as it happens with a minimal kernel before this commit) isn't nice
either.  I'll try to look after that, too, just mentioning it here... 

This is expected as the driver has to reset the link and you'll lose SoL
for a few seconds until link comes back up.  We can look into an
enhancement to not touch the link if it is already in a good state when
the driver comes up.