RE: [PATCH CFT 00/30] Initial round of Freescale FEC ethernet patches

From: Russell King - ARM Linux <redacted> Data: Friday, June 27, 2014 11:16 PM

To: linux-arm-kernel@lists.infradead.org; netdev@vger.kernel.org
Cc: Duan Fugang-B38611
Subject: [PATCH CFT 00/30] Initial round of Freescale FEC ethernet patches

This is v2 of my initial round of patches (roughly half of my total patch
set) for the Freescale FEC driver.

I'm sending this set out for comments and testing.  So far, I have had
only one ack for one patch in this series, this is pretty poor, so I'm now
sending it with a CFT tag instead.

I haven't changed too much - I've fixed the bug which Andy spotted in the
transmit handling, but otherwise the patches are much the same.

The remainder of the text is as per my previous message, but with updated
diffstat:

One of my motivations for only sending half is to get this half into a
state where DaveM is happy to merge it before I sort out the remainder.
There's quite a lot here, so bear with me on this.

I've tried to sort the fixes before the cleanups as best I can, but
reordering the series is a full-time job due to it's size - it's taken
from Monday until now to get this far with it, so I'm hoping that there
won't be any "you should rearrange the patches as X" comments.

While the original series was well tested during it's original development,
including with performance tests on each patch, that testing and
validation has been lost due to the changes during the last merge window,
and subsequent rebasing and updating of the patches.

The series is based on v3.16-rc1, and as such, I have added Andy's
checksum fix to the start of the series.  This patch is not strictly part
of the RFC, but is included because my complete patch series needs to
account for that change.

Some of these patches are to fix theoretical problems in the driver (ones
which have been found via a review of the code) others address real
observable problems (such as poor half-duplex performance.)

Towards the end of this series, I have included a patch which was
initially at the beginning of the series for dumping out the state of the
transmit ring, which is very useful to debug transmit problems.
This was acceptable when the transmit ring was between 16 and 128
descriptors, but during the recent merge window, this was increased to
512 descriptors, so it will now print around 512 lines to the kernel
message log on transmit timeout.  I'm not entirely convinced this is a
good idea - maybe it should become optional, or maybe the timed-out ring
status should be available via debugfs, but that's a problem to retrieve
if you're running NFS rootfs and the timeout doesn't recover properly.

This series of patches is also available from the following *unstable* git
branch - unstable as it's provided for convenience so you don't have to
apply all these patches individually, unstable as the patches need to have
attributations added, unstable because DaveM will probably want to apply
them as patches to his tree:

 git://ftp.arm.linux.org.uk/~rmk/linux-arm.git fec-testing

drivers/net/ethernet/freescale/fec.h      |  10 +-
drivers/net/ethernet/freescale/fec_main.c | 382 +++++++++++++++++--------
-----
2 files changed, 224 insertions(+), 168 deletions(-)

Hi, Russell,

The V2 patch set are fine for me. Thanks for your clean for the driver.

Acked-by: Fugang Duan <redacted>

Thanks,
Andy