[PATCH 4/4] watchdog: sama5d4: Add comment explaining what happens on resume
Guenter Roeck
linux at roeck-us.net
Sat Mar 4 07:07:28 PST 2017
On 03/02/2017 09:31 AM, Alexandre Belloni wrote:
> Because suspending to RAM may lose the register values, they are restored
> on resume. This is currently done unconditionally because there is
> currently no way to know (from the driver) whether they have really been
> lost or are still valid. Writing MR also pings the watchdog and this may
> not be what is expected so add a comment explaining why it happens.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
Reviewed-by: Guenter Roeck <linux at roeck-us.net>
> ---
> drivers/watchdog/sama5d4_wdt.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
> index d710014f3b7d..0ae947c3d7bc 100644
> --- a/drivers/watchdog/sama5d4_wdt.c
> +++ b/drivers/watchdog/sama5d4_wdt.c
> @@ -300,6 +300,11 @@ static int sama5d4_wdt_resume(struct device *dev)
> {
> struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
>
> + /*
> + * FIXME: writing MR also pings the watchdog which may not be desired.
> + * This should only be done when the registers are lost on suspend but
> + * there is no way to get this information right now.
> + */
> sama5d4_wdt_init(wdt);
>
> return 0;
>
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