On 1/20/16 2:43 PM, Julian Calaby wrote:
Hi Wim Coekaerts,
On Thu, Jan 21, 2016 at 7:30 AM, <wim.coekaerts@xxxxxxxxxx> wrote:
From: Wim Coekaerts <wim.coekaerts@xxxxxxxxxx>
This adds a simple watchdog timer for the SPARC sunv4 architecture.
Export the sun4v_mach_set_watchdog() hv call, and add the target.
The driver is implemented using the new watchdog api framework.
Signed-off-by: Wim Coekaerts <wim.coekaerts@xxxxxxxxxx>
This all looks _much_ better.
There's nothing glaringly wrong with the code like the last version,
so I've only got a couple of general questions:
1. Is the platform device and driver necessary? Can't you just
register the watchdog device directly from sun4v_wdt_init_module()?
2. If the platform device is unnecessary, do you still need a struct
watchdog_device in struct sun4v_wdt? I.e. does the watchdog core stop
watchdogs when you call watchdog_unregister_device()? (Or could you
refactor to not require it?)
3. Is it possible to get the data for sun4v_wdt_get_timeleft() by
calling some other sun4v_mach_*() function?
4. You still don't use the result returned through the second
parameter of sun4v_mach_set_watchdog(). Does this number have any
meaning and would it make sense to store it in ->expires instead of
calculating it from the timeout?
actually one thing we could do:
we could change the sun4v_mach_set_watchdog hv call like below (thanks
Greg Onufer for this tweak)
diff --git a/arch/sparc/kernel/hvcalls.S b/arch/sparc/kernel/hvcalls.S
index caedf83..b7122a2 100644
--- a/arch/sparc/kernel/hvcalls.S
+++ b/arch/sparc/kernel/hvcalls.S
@@ -338,8 +338,9 @@ ENTRY(sun4v_mach_set_watchdog)
mov %o1, %o4
mov HV_FAST_MACH_SET_WATCHDOG, %o5
ta HV_FAST_TRAP
- stx %o1, [%o4]
- retl
+ brnz,a,pn %o4, 0f
+ stx %o1, [%o4]
+0: retl
nop
ENDPROC(sun4v_mach_set_watchdog)
and then do sun4v_mach_set_watchdog(timeout, NULL) instead.
I'd be fine with that if that's preferred.
Dave?
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