RE: [PATCH 1/2] watchdog: rzg2l_wdt: Issue a reset before we put the PM clocks

From: Biju Das
Date: Wed Feb 08 2023 - 02:52:18 EST


Hi Fabrizio,

Thanks for the patch.

> Subject: [PATCH 1/2] watchdog: rzg2l_wdt: Issue a reset before we put the PM
> clocks
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> On RZ/Five SoC it was observed that setting timeout (to say 1 sec) wouldn't
> reset the system.
>
> The procedure described in the HW manual (Procedure for Activating Modules)
> for activating the target module states we need to start supply of the clock
> module before applying the reset signal. This patch makes sure we follow the
> same procedure to clear the registers of the WDT module, fixing the issues
> seen on RZ/Five SoC.
>
> While at it re-used rzg2l_wdt_stop() in rzg2l_wdt_set_timeout() as it has
> the same function calls.
>
> Fixes: 4055ee81009e ("watchdog: rzg2l_wdt: Add set_timeout callback")
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>

Cheers,
Biju

> ---
> drivers/watchdog/rzg2l_wdt.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
> index 974a4194a8fd..ceca42db0837 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -115,25 +115,23 @@ static int rzg2l_wdt_stop(struct watchdog_device
> *wdev) {
> struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
>
> - pm_runtime_put(wdev->parent);
> reset_control_reset(priv->rstc);
> + pm_runtime_put(wdev->parent);
>
> return 0;
> }
>
> static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int
> timeout) {
> - struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> -
> wdev->timeout = timeout;
>
> /*
> * If the watchdog is active, reset the module for updating the WDTSET
> - * register so that it is updated with new timeout values.
> + * register by calling rzg2l_wdt_stop() (which internally calls
> reset_control_reset()
> + * to reset the module) so that it is updated with new timeout values.
> */
> if (watchdog_active(wdev)) {
> - pm_runtime_put(wdev->parent);
> - reset_control_reset(priv->rstc);
> + rzg2l_wdt_stop(wdev);
> rzg2l_wdt_start(wdev);
> }
>
> --
> 2.34.1