Subject: Re: [PATCH net 0/3] net: stmmac: Misc fixes

From: Niklas Cassel <[email-masked]>
Date: Tue, 5 Feb 2019 23:05:44 +0100

On Wed, Jan 30, 2019 at 03:54:18PM +0100, Jose Abreu wrote:
> 
> Some misc fixes for stmmac targeting -net.
> 
> Cc: Joao Pinto <[email-masked]>
> Cc: David S. Miller <[email-masked]>
> Cc: Giuseppe Cavallaro <[email-masked]>
> Cc: Alexandre Torgue <[email-masked]>
> 
> Jose Abreu (3):
>   net: stmmac: Fallback to Platform Data clock in Watchdog conversion
>   net: stmmac: Send TSO packets always from Queue 0
>   net: stmmac: Disable EEE mode earlier in XMIT callback

Hello Jose,

Thanks for your great work of improving the stmmac driver.

Unfortunately, I'm seeing that a lot of important stmmac fixes
aren't getting backported to stable kernels.

I think that the problem is that a lot of stmmac commit messages do
not clearly indicate what happens if these patches are not included.

See netdev FAQ:

Q: I have created a network patch and I think it should be backported to
   stable.  Should I add a "Cc: [email-masked]" like the references
   in the kernel's Documentation/ directory say?

A: No.  See above answer.  In short, if you think it really belongs in
   stable, then ensure you write a decent commit log that describes who
   gets impacted by the bugfix and how it manifests itself, and when the
   bug was introduced.  If you do that properly, then the commit will
   get handled appropriately and most likely get put in the patchworks
   stable queue if it really warrants it.

Could you please tell me what happens if I don't include
"net: stmmac: Disable EEE mode earlier in XMIT callback" ?

likewise if I don't include "net: stmmac: Send TSO packets always from
Queue 0" ?

I assume that I will get a TX timeout if I try to send a TSO packet
from a queue that does not support it?

Also, we already define the TX queues in the snps,mtl-tx-config:
Documentation/devicetree/bindings/net/stmmac.txt

Wouldn't it be possible to add a snps,tso-capable property for each tx
queue node that supports tso?

Kind regards,
Niklas

> 
>  drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 14 ++++++++++----
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c    | 17 +++++++++++++----
>  include/linux/stmmac.h                               |  1 +
>  3 files changed, 24 insertions(+), 8 deletions(-)
> 
> -- 
> 2.7.4
>