[PATCH net-next 5/7] net:fec: add support for dumping transmit ring on timeout

Russell King - ARM Linux linux at arm.linux.org.uk
Tue Apr 29 07:32:44 PDT 2014

On Tue, Apr 29, 2014 at 09:22:13AM -0500, Frank Li wrote:
> On Tue, Apr 29, 2014 at 9:15 AM, Russell King - ARM Linux
> <linux at arm.linux.org.uk> wrote:
> > On Tue, Apr 29, 2014 at 02:01:54PM +0000, David Laight wrote:
> >> From: Frank ...
> >> > > You probably want the read and write indexes as well.
> >> >
> >> >                      bdp == fep->cur_tx ? 'S' : ' ',
> >> >                      bdp == fep->dirty_tx ? 'H' : ' ',
> >> >
> >> > Above code already print read and write index. 'S', 'H'
> >>
> >> Gah I must be asleep!
> >> Something made be think that was to do with the ring ownership bit!
> >
> > Err, what's going on... this is my patch.  If it's been submitted by
> > others, why wasn't its submission at least Cc'd to me?
> I added " --to rmk+kernel at arm.linux.org.uk" when I send patch.
> I don't know what's wrong.

Yes... I guess you don't know what went wrong because you'll never know
if it failed to be delivered, because you sent them with an envelope
address of "b20596 at shlinux1.ap.freescale.net" which doesn't actually
exist.  Therefore, DSNs can't be returned to you.

> I ask you if need someone help send to david millar before.

You did, but I didn't agree to it.  I did point out that they need a
certain amount of rework first:

  I know they need to re-worked to convert unsigned -> unsigned int before
  David sees them, otherwise it'd be an instant review failure.  Doing the
  conversion is the easy bit, doing it without hitting the 80 column limit
  is much harder...

Some of them need a little more work in addition to that before being
sent to David.

I've also subsequently received in private email one issue which indicates
a problem with the patch set - as yet I've not been able to look at it,
but it sounds like the RX ring is full, but NAPI is in hard-irq mode,
and the hardware won't deliver an IRQ without free space in the RX ring.

Since people have got wind that I've been looking at this driver, everyone
has started sending their various FEC issues directly to me...

FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

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