[PATCH 2/4] watchdog: orion: Use the reference clock on Armada 375 SoC

[Andrew Lunn]

On Wed, Oct 22, 2014 at 07:41:27PM -0300, Ezequiel Garcia wrote:
> On 10/22/2014 11:02 AM, Andrew Lunn wrote:
> > On Wed, Oct 22, 2014 at 10:34:42AM -0300, Ezequiel Garcia wrote:
> >> The 25 MHz reference clock has better stability so its use is preferred over the
> >> core clock. Changes the Armada 375 clock initialization to use this reference
> >> clock. To ensure the driver is compatible with an old devicetree, also provide
> >> a fallback path which will silently return to the previous behavior.
> > 
> > Hi Ezequiel
> > 
> > There is now quite a lot of code in orion_wdt.c which is not relevant
> > to Orion5x and Kirkwood. Would it be possible to put some of it inside
> > a #ifdef MACH_MVEBU_V7?
> > 
> 
> Hum.. I found ifdefs scary, so I tend to avoid them if at all possible.
> Just did a quick hack enclosing all the armada-xxx stuff around #if 0
> and here's the result:
> 
> $ ./scripts/bloat-o-meter ~/linux/.builds/mvebu_v7/drivers/watchdog/orion_wdt.o ~/linux/.builds/orion5x/drivers/watchdog/orion_wdt.o
> add/remove: 0/0 grow/shrink: 1/4 up/down: 12/-80 (-68)
> function                                     old     new   delta
> orion_wdt_probe                              732     744     +12
> orion_wdt_get_timeleft                        44      40      -4
> orion_enabled                                 68      60      -8
> orion_start                                  120      88     -32
> orion_wdt_ping                                80      44     -36

Hi Ezequiel

I did a similar test:

size drivers/watchdog/orion_wdt.o-*
   text	   data	    bss	    dec	    hex	filename
   4428	    100       1    4529    11b1	drivers/watchdog/orion_wdt.o-full-fat
   2324	    100	      1    2425	    979	drivers/watchdog/orion_wdt.o-skimmed

So for v5 kirkwood/orion5x, there is about 90% overhead from the v7
code, in the text section. This is for -rc1 code, before adding any
more v7 code in this patchset.

I don't think the #ifdef's look that scary.

  Andrew