On 01/21/2016 10:42 PM, Guenter Roeck wrote:Correct. In your case it may be sufficient to just set the 'timeout' variable
This implies that setting the timeout would start the watchdog,
which is inappropriate (the timeout can be set while the watchdog
Also, setting the timeout sets both the resolution _and_ the timeout,
which is probably unnecessary when starting or pinging the watchdog.
Help me understand the functionality of the watchdog operations briefly
since I'm relatively new to the interface. Is it proper to say that the
start callback starts (and in my case also pings) the watchdog based on
the value of the previously configured timeout member, while the
set_timeout callback merely sets the timeout member itself to the
correct value in seconds accordingly to the watchdog timer's resolution?
So how about DMI ? This is a PC, after all, so it should be possible+ const unsigned base = 0x564;
+ const unsigned extent = 5;
+ const char *const name = dev_name(dev);
What is the value of those const variables ? Why not just use dev_name() and defines ?
+ int err;
Is there a means to detect if this is the correct system ? DMI, maybe ?
Blindly instantiating the driver seems to be a bit risky and should be avoided
Unfortunately, the watchdog timer hardware lacks probing capabilities;
the documentation for the motherboard indicates that the watchdog timer
is exposed over an ISA-style I/O-mapped port address. In other words,
the watchdog timer is non-hotpluggable.
I agree that carrying around the constant values in the private dataIt is the common and established approach to use defines (you use a define
structure is somewhat unnecessary, so I'll give them global scope over
the file. I'm hesitant to lose the type-safety of C variables; is there
a reason to prefer preprocessor defines over const-qualified variables?
I didn't want to suggest that. One option would be to set+ err = watchdog_init_timeout(&wdt->wdd, timeout, dev);
+ if (err)
+ goto err_init_timeout;
A more tolerant implementation would set the default timeout.
Should I remove the timeout module parameter entirely, and simply
initialize the watchdog_device timeout member to the default timeout I
want (e.g. wdt->wdd.timeout = 60)? Would I still need to call
watchdog_init_timeout in that case?
Ah yes, my mistake. The idea is that another driver (usually a platformHave you considered using module_platform_driver_probe() ?
For some reason, I was under the impression that I must allocate a
platform_device before calling platform_driver_probe. I'll try
module_platform_driver_probe since that would indeed be far simpler if
the platform_device setup code is unnecessary.
Not sure I understand what that has to do with hotplug. Almost allNo MODULE_ALIAS ?
Since the watchdog timer hardware is non-hotpluggable, I'm not sure I
should add a MODULE_ALIAS for autoloading the module.