Re: [RFC PATCH 3/9] net: dsa: hellcreek: Add PTP clock support

Hi Jakub,

On Thu Jun 18 2020, Jakub Kicinski wrote:

On Thu, 18 Jun 2020 08:40:23 +0200 Kurt Kanzenbach wrote:

quoted

From: Kamil Alkhouri <redacted>

The switch has internal PTP hardware clocks. Add support for it. There are three
clocks:

 * Synchronized
 * Syntonized
 * Free running

Currently the synchronized clock is exported to user space which is a good
default for the beginning. The free running clock might be exported later
e.g. for implementing 802.1AS-2011/2020 Time Aware Bridges (TAB). The switch
also supports cross time stamping for that purpose.

The implementation adds support setting/getting the time as well as offset and
frequency adjustments. However, the clock only holds a partial timeofday
timestamp. This is why we track the seconds completely in software (see overflow
work and last_ts).

Furthermore, add the PTP multicast addresses into the FDB to forward that
packages only to the CPU port where they are processed by a PTP program.

Signed-off-by: Kamil Alkhouri <redacted>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>

Please make sure each patch in the series builds cleanly with the W=1
C=1 flags. Here we have:

../drivers/net/dsa/hirschmann/hellcreek_ptp.c: In function ‘__hellcreek_ptp_clock_read’:
../drivers/net/dsa/hirschmann/hellcreek_ptp.c:30:28: warning: variable ‘sech’ set but not used [-Wunused-but-set-variable]
   30 |  u16 nsl, nsh, secl, secm, sech;
      |                            ^~~~
../drivers/net/dsa/hirschmann/hellcreek_ptp.c:30:22: warning: variable ‘secm’ set but not used [-Wunused-but-set-variable]
   30 |  u16 nsl, nsh, secl, secm, sech;
      |                      ^~~~
../drivers/net/dsa/hirschmann/hellcreek_ptp.c:30:16: warning: variable ‘secl’ set but not used [-Wunused-but-set-variable]
   30 |  u16 nsl, nsh, secl, secm, sech;
      |                ^~~~

Next patch adds a few more.

Sorry, I did test with C=1 only. I'll fix it.

Thanks,
Kurt