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Date: Tue, 7 May 2019 01:20:19 +0000
From: Anson Huang <anson.huang@....com>
To: Guenter Roeck <linux@...ck-us.net>
CC: "robh+dt@...nel.org" <robh+dt@...nel.org>,
"mark.rutland@....com" <mark.rutland@....com>,
"wim@...ux-watchdog.org" <wim@...ux-watchdog.org>,
"shawnguo@...nel.org" <shawnguo@...nel.org>,
"s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
"kernel@...gutronix.de" <kernel@...gutronix.de>,
"festevam@...il.com" <festevam@...il.com>,
Aisheng Dong <aisheng.dong@....com>,
"ulf.hansson@...aro.org" <ulf.hansson@...aro.org>,
"sboyd@...nel.org" <sboyd@...nel.org>,
Daniel Baluta <daniel.baluta@....com>,
Peng Fan <peng.fan@....com>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-watchdog@...r.kernel.org" <linux-watchdog@...r.kernel.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
dl-linux-imx <linux-imx@....com>
Subject: RE: [PATCH V3 3/3] watchdog: imx_sc: Add pretimeout support
Hi, Guenter
> -----Original Message-----
> From: Guenter Roeck [mailto:groeck7@...il.com] On Behalf Of Guenter
> Roeck
> Sent: Tuesday, May 7, 2019 2:28 AM
> To: Anson Huang <anson.huang@....com>
> Cc: robh+dt@...nel.org; mark.rutland@....com; wim@...ux-watchdog.org;
> shawnguo@...nel.org; s.hauer@...gutronix.de; kernel@...gutronix.de;
> festevam@...il.com; Aisheng Dong <aisheng.dong@....com>;
> ulf.hansson@...aro.org; sboyd@...nel.org; Daniel Baluta
> <daniel.baluta@....com>; Peng Fan <peng.fan@....com>;
> devicetree@...r.kernel.org; linux-kernel@...r.kernel.org; linux-
> watchdog@...r.kernel.org; linux-arm-kernel@...ts.infradead.org; dl-linux-
> imx <linux-imx@....com>
> Subject: Re: [PATCH V3 3/3] watchdog: imx_sc: Add pretimeout support
>
> On Sun, May 05, 2019 at 02:15:00AM +0000, Anson Huang wrote:
> > i.MX system controller watchdog can support pretimeout IRQ via general
> > SCU MU IRQ, it depends on IMX_SCU and driver MUST be probed after SCU
> > IPC ready, then enable corresponding SCU IRQ group and register SCU
> > IRQ notifier, when watchdog pretimeout IRQ fires, SCU MU IRQ will be
> > handled and watchdog pretimeout notifier will be called to handle the
> > event.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@....com>
> > ---
> > No change.
> > ---
> > drivers/watchdog/Kconfig | 1 +
> > drivers/watchdog/imx_sc_wdt.c | 114
> > ++++++++++++++++++++++++++++++++++--------
> > 2 files changed, 95 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index
> > e19960a..dbc74e1 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -710,6 +710,7 @@ config IMX2_WDT
> > config IMX_SC_WDT
> > tristate "IMX SC Watchdog"
> > depends on HAVE_ARM_SMCCC
> > + depends on IMX_SCU
> > select WATCHDOG_CORE
> > help
> > This is the driver for the system controller watchdog diff --git
> > a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c index
> > 49848b6..d8493a3 100644
> > --- a/drivers/watchdog/imx_sc_wdt.c
> > +++ b/drivers/watchdog/imx_sc_wdt.c
> > @@ -4,6 +4,7 @@
> > */
> >
> > #include <linux/arm-smccc.h>
> > +#include <linux/firmware/imx/sci.h>
> > #include <linux/io.h>
> > #include <linux/init.h>
> > #include <linux/kernel.h>
> > @@ -33,11 +34,19 @@
> >
> > #define SC_TIMER_WDOG_ACTION_PARTITION 0
> >
> > +#define SC_IRQ_WDOG 1
> > +#define SC_IRQ_GROUP_WDOG 1
> > +
> > static bool nowayout = WATCHDOG_NOWAYOUT;
> module_param(nowayout,
> > bool, 0000); MODULE_PARM_DESC(nowayout, "Watchdog cannot be
> stopped
> > once started (default="
> > __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> >
> > +struct imx_sc_wdt_device {
> > + struct watchdog_device wdd;
> > + struct notifier_block wdt_notifier;
> > +};
> > +
> > static int imx_sc_wdt_ping(struct watchdog_device *wdog) {
> > struct arm_smccc_res res;
> > @@ -85,24 +94,66 @@ static int imx_sc_wdt_set_timeout(struct
> watchdog_device *wdog,
> > return res.a0 ? -EACCES : 0;
> > }
> >
> > +static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog,
> > + unsigned int pretimeout)
> > +{
> > + struct arm_smccc_res res;
> > +
> > + arm_smccc_smc(IMX_SIP_TIMER,
> IMX_SIP_TIMER_SET_PRETIME_WDOG,
> > + pretimeout * 1000, 0, 0, 0, 0, 0, &res);
> > + if (res.a0)
> > + return -EACCES;
> > +
> > + wdog->pretimeout = pretimeout;
> > +
> > + return 0;
> > +}
> > +
> > +static int imx_sc_wdt_notify(struct notifier_block *nb,
> > + unsigned long event, void *group) {
> > + struct imx_sc_wdt_device *imx_sc_wdd =
> > + container_of(nb,
> > + struct imx_sc_wdt_device,
> > + wdt_notifier);
> > +
> > + if (event & SC_IRQ_WDOG &&
> > + *(u8 *)group == SC_IRQ_GROUP_WDOG)
> > + watchdog_notify_pretimeout(&imx_sc_wdd->wdd);
> > +
> > + return 0;
> > +}
> > +
> > +static void imx_sc_wdt_action(void *data) {
> > + struct notifier_block *wdt_notifier = data;
> > +
> > + imx_scu_irq_unregister_notifier(wdt_notifier);
> > + imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
> > + SC_IRQ_WDOG,
> > + false);
> > +}
> > +
> > static const struct watchdog_ops imx_sc_wdt_ops = {
> > .owner = THIS_MODULE,
> > .start = imx_sc_wdt_start,
> > .stop = imx_sc_wdt_stop,
> > .ping = imx_sc_wdt_ping,
> > .set_timeout = imx_sc_wdt_set_timeout,
> > + .set_pretimeout = imx_sc_wdt_set_pretimeout,
> > };
> >
> > -static const struct watchdog_info imx_sc_wdt_info = {
> > +static struct watchdog_info imx_sc_wdt_info = {
> > .identity = "i.MX SC watchdog timer",
> > .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> > - WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT,
> > + WDIOF_MAGICCLOSE,
> > };
> >
> > static int imx_sc_wdt_probe(struct platform_device *pdev) {
> > + struct imx_sc_wdt_device *imx_sc_wdd;
> > + struct watchdog_device *wdog;
> > struct device *dev = &pdev->dev;
> > - struct watchdog_device *imx_sc_wdd;
> > int ret;
> >
> > imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL);
> @@
> > -111,42 +162,65 @@ static int imx_sc_wdt_probe(struct platform_device
> > *pdev)
> >
> > platform_set_drvdata(pdev, imx_sc_wdd);
> >
> > - imx_sc_wdd->info = &imx_sc_wdt_info;
> > - imx_sc_wdd->ops = &imx_sc_wdt_ops;
> > - imx_sc_wdd->min_timeout = 1;
> > - imx_sc_wdd->max_timeout = MAX_TIMEOUT;
> > - imx_sc_wdd->parent = dev;
> > - imx_sc_wdd->timeout = DEFAULT_TIMEOUT;
> > + wdog = &imx_sc_wdd->wdd;
> > + wdog->info = &imx_sc_wdt_info;
> > + wdog->ops = &imx_sc_wdt_ops;
> > + wdog->min_timeout = 1;
> > + wdog->max_timeout = MAX_TIMEOUT;
> > + wdog->parent = dev;
> > + wdog->timeout = DEFAULT_TIMEOUT;
> >
> > - watchdog_init_timeout(imx_sc_wdd, 0, dev);
> > - watchdog_stop_on_reboot(imx_sc_wdd);
> > - watchdog_stop_on_unregister(imx_sc_wdd);
> > + watchdog_init_timeout(wdog, 0, dev);
> > + watchdog_stop_on_reboot(wdog);
> > + watchdog_stop_on_unregister(wdog);
> >
> > - ret = devm_watchdog_register_device(dev, imx_sc_wdd);
> > + ret = devm_watchdog_register_device(dev, wdog);
> > if (ret) {
> > dev_err(dev, "Failed to register watchdog device\n");
> > return ret;
> > }
> >
> > - return 0;
> > + ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
> > + SC_IRQ_WDOG,
> > + true);
> > + if (ret) {
> > + dev_warn(dev, "Enable irq failed, pretimeout NOT
> supported\n");
> > + return 0;
> > + }
> > +
> > + imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify;
> > + ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier);
> > + if (ret) {
> > + imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
> > + SC_IRQ_WDOG,
> > + false);
> > + dev_warn(dev,
> > + "Register irq notifier failed, pretimeout NOT
> supported\n");
> > + return 0;
> > + }
> > +
> > + imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT;
> > + ret = devm_add_action(dev, imx_sc_wdt_action,
> > + &imx_sc_wdd->wdt_notifier);
>
> This needs devm_add_action_or_reset() because otherwise the notifier
> would not be removed, and the interrupt group would not be disabled.
Right, fix it in V4.
>
> > + return ret;
>
> This should not return an error. Accepting that the notifier can not be
> registered and that the irq group can not be enabled but bailing out if
> devm_add_action() fails is inconsistent.
>
Agreed, the pretimeout function should ONLT be enabled after the notifier
register, irq group enable and add action all success, so I use below code
in V4, please help review, thanks,
+
+ ret = devm_add_action_or_reset(dev, imx_sc_wdt_action,
+ &imx_sc_wdd->wdt_notifier);
+ if (!ret)
+ imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT;
+ else
+ dev_warn(dev, "Add action failed, pretimeout NOT supported\n");
+
return 0;
Anson.
> Guenter
>
> > }
> >
> > static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) {
> > - struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> > + struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
> >
> > - if (watchdog_active(imx_sc_wdd))
> > - imx_sc_wdt_stop(imx_sc_wdd);
> > + if (watchdog_active(&imx_sc_wdd->wdd))
> > + imx_sc_wdt_stop(&imx_sc_wdd->wdd);
> >
> > return 0;
> > }
> >
> > static int __maybe_unused imx_sc_wdt_resume(struct device *dev) {
> > - struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> > + struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
> >
> > - if (watchdog_active(imx_sc_wdd))
> > - imx_sc_wdt_start(imx_sc_wdd);
> > + if (watchdog_active(&imx_sc_wdd->wdd))
> > + imx_sc_wdt_start(&imx_sc_wdd->wdd);
> >
> > return 0;
> > }
> > --
> > 2.7.4
> >
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