| Message ID | 1520263826-1937-3-git-send-email-fabrizio.castro@bp.renesas.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
> Since Simon only reviewed Geert's patch, and Wolfram and Guenter only reviewed > earlier versions of this patch, I am not including their "Reviewed-by" as they > may disagree with the final result. I don't :) Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
On Mon, Mar 05, 2018 at 03:30:25PM +0000, Fabrizio Castro wrote: > Due to commits: > * "ARM: shmobile: Add watchdog support", > * "ARM: shmobile: rcar-gen2: Add watchdog support", and > * "soc: renesas: rcar-rst: Enable watchdog as reset trigger for Gen2", > we now have everything we needed for the watchdog to work on Gen2 and > RZ/G1. > > However, on early revisions of some R-Car Gen2 SoCs, and depending on SMP > configuration, the system may fail to restart on watchdog time-out, and > lock up instead. > > Specifically: > - On R-Car H2 ES1.0 and M2-W ES1.0, watchdog restart fails unless > only the first CPU core is in use (using e.g. the "maxcpus=1" kernel > commandline option). > - On R-Car V2H ES1.1, watchdog restart fails unless SMP is disabled > completely (using CONFIG_SMP=n during build configuration, or using > the "nosmp" or "maxcpus=0" kernel commandline options). > > This commit adds "renesas,rcar-gen2-wdt" as compatible string for R-Car > Gen2 and RZ/G1, but also prevents the system from using the watchdog > driver in cases where the system would fail to restart by blacklisting > the affected SoCs, using the minimum known working revisions (ES2.0 on R-Car > H2, and ES3.0 on M2-W), and taking the actual SMP software configuration > into account. > > Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> > Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com> > [Geert: blacklisting logic] > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > v7->v8: > * folded patch "watchdog: renesas_wdt: Blacklist early R-Car Gen2 SoCs" from > Geert into this patch. > > Since Simon only reviewed Geert's patch, and Wolfram and Guenter only reviewed > earlier versions of this patch, I am not including their "Reviewed-by" as they > may disagree with the final result. > Reviewed-by: Guenter Roeck <linux@roeck-us.net> > Thanks, > Fab > > drivers/watchdog/renesas_wdt.c | 49 +++++++++++++++++++++++++++++++++++++----- > 1 file changed, 44 insertions(+), 5 deletions(-) > > diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c > index 024d54e..0dede5b 100644 > --- a/drivers/watchdog/renesas_wdt.c > +++ b/drivers/watchdog/renesas_wdt.c > @@ -16,6 +16,8 @@ > #include <linux/of.h> > #include <linux/platform_device.h> > #include <linux/pm_runtime.h> > +#include <linux/smp.h> > +#include <linux/sys_soc.h> > #include <linux/watchdog.h> > > #define RWTCNT 0 > @@ -121,6 +123,44 @@ static const struct watchdog_ops rwdt_ops = { > .get_timeleft = rwdt_get_timeleft, > }; > > +#if defined(CONFIG_ARCH_RCAR_GEN2) && defined(CONFIG_SMP) > +/* > + * Watchdog-reset integration is broken on early revisions of R-Car Gen2 SoCs > + */ > +static const struct soc_device_attribute rwdt_quirks_match[] = { > + { > + .soc_id = "r8a7790", > + .revision = "ES1.*", > + .data = (void *)1, /* needs single CPU */ > + }, { > + .soc_id = "r8a7791", > + .revision = "ES[12].*", > + .data = (void *)1, /* needs single CPU */ > + }, { > + .soc_id = "r8a7792", > + .revision = "*", > + .data = (void *)0, /* needs SMP disabled */ > + }, > + { /* sentinel */ } > +}; > + > +static bool rwdt_blacklisted(struct device *dev) > +{ > + const struct soc_device_attribute *attr; > + > + attr = soc_device_match(rwdt_quirks_match); > + if (attr && setup_max_cpus > (uintptr_t)attr->data) { > + dev_info(dev, "Watchdog blacklisted on %s %s\n", attr->soc_id, > + attr->revision); > + return true; > + } > + > + return false; > +} > +#else /* !CONFIG_ARCH_RCAR_GEN2 || !CONFIG_SMP */ > +static inline bool rwdt_blacklisted(struct device *dev) { return false; } > +#endif /* !CONFIG_ARCH_RCAR_GEN2 || !CONFIG_SMP */ > + > static int rwdt_probe(struct platform_device *pdev) > { > struct rwdt_priv *priv; > @@ -129,6 +169,9 @@ static int rwdt_probe(struct platform_device *pdev) > unsigned long clks_per_sec; > int ret, i; > > + if (rwdt_blacklisted(&pdev->dev)) > + return -ENODEV; > + > priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > if (!priv) > return -ENOMEM; > @@ -228,12 +271,8 @@ static int __maybe_unused rwdt_resume(struct device *dev) > > static SIMPLE_DEV_PM_OPS(rwdt_pm_ops, rwdt_suspend, rwdt_resume); > > -/* > - * This driver does also fit for R-Car Gen2 (r8a779[0-4]) WDT. However, for SMP > - * to work there, one also needs a RESET (RST) driver which does not exist yet > - * due to HW issues. This needs to be solved before adding compatibles here. > - */ > static const struct of_device_id rwdt_ids[] = { > + { .compatible = "renesas,rcar-gen2-wdt", }, > { .compatible = "renesas,rcar-gen3-wdt", }, > { /* sentinel */ } > }; > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c index 024d54e..0dede5b 100644 --- a/drivers/watchdog/renesas_wdt.c +++ b/drivers/watchdog/renesas_wdt.c @@ -16,6 +16,8 @@ #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> +#include <linux/smp.h> +#include <linux/sys_soc.h> #include <linux/watchdog.h> #define RWTCNT 0 @@ -121,6 +123,44 @@ static const struct watchdog_ops rwdt_ops = { .get_timeleft = rwdt_get_timeleft, }; +#if defined(CONFIG_ARCH_RCAR_GEN2) && defined(CONFIG_SMP) +/* + * Watchdog-reset integration is broken on early revisions of R-Car Gen2 SoCs + */ +static const struct soc_device_attribute rwdt_quirks_match[] = { + { + .soc_id = "r8a7790", + .revision = "ES1.*", + .data = (void *)1, /* needs single CPU */ + }, { + .soc_id = "r8a7791", + .revision = "ES[12].*", + .data = (void *)1, /* needs single CPU */ + }, { + .soc_id = "r8a7792", + .revision = "*", + .data = (void *)0, /* needs SMP disabled */ + }, + { /* sentinel */ } +}; + +static bool rwdt_blacklisted(struct device *dev) +{ + const struct soc_device_attribute *attr; + + attr = soc_device_match(rwdt_quirks_match); + if (attr && setup_max_cpus > (uintptr_t)attr->data) { + dev_info(dev, "Watchdog blacklisted on %s %s\n", attr->soc_id, + attr->revision); + return true; + } + + return false; +} +#else /* !CONFIG_ARCH_RCAR_GEN2 || !CONFIG_SMP */ +static inline bool rwdt_blacklisted(struct device *dev) { return false; } +#endif /* !CONFIG_ARCH_RCAR_GEN2 || !CONFIG_SMP */ + static int rwdt_probe(struct platform_device *pdev) { struct rwdt_priv *priv; @@ -129,6 +169,9 @@ static int rwdt_probe(struct platform_device *pdev) unsigned long clks_per_sec; int ret, i; + if (rwdt_blacklisted(&pdev->dev)) + return -ENODEV; + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; @@ -228,12 +271,8 @@ static int __maybe_unused rwdt_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(rwdt_pm_ops, rwdt_suspend, rwdt_resume); -/* - * This driver does also fit for R-Car Gen2 (r8a779[0-4]) WDT. However, for SMP - * to work there, one also needs a RESET (RST) driver which does not exist yet - * due to HW issues. This needs to be solved before adding compatibles here. - */ static const struct of_device_id rwdt_ids[] = { + { .compatible = "renesas,rcar-gen2-wdt", }, { .compatible = "renesas,rcar-gen3-wdt", }, { /* sentinel */ } };
Due to commits: * "ARM: shmobile: Add watchdog support", * "ARM: shmobile: rcar-gen2: Add watchdog support", and * "soc: renesas: rcar-rst: Enable watchdog as reset trigger for Gen2", we now have everything we needed for the watchdog to work on Gen2 and RZ/G1. However, on early revisions of some R-Car Gen2 SoCs, and depending on SMP configuration, the system may fail to restart on watchdog time-out, and lock up instead. Specifically: - On R-Car H2 ES1.0 and M2-W ES1.0, watchdog restart fails unless only the first CPU core is in use (using e.g. the "maxcpus=1" kernel commandline option). - On R-Car V2H ES1.1, watchdog restart fails unless SMP is disabled completely (using CONFIG_SMP=n during build configuration, or using the "nosmp" or "maxcpus=0" kernel commandline options). This commit adds "renesas,rcar-gen2-wdt" as compatible string for R-Car Gen2 and RZ/G1, but also prevents the system from using the watchdog driver in cases where the system would fail to restart by blacklisting the affected SoCs, using the minimum known working revisions (ES2.0 on R-Car H2, and ES3.0 on M2-W), and taking the actual SMP software configuration into account. Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com> [Geert: blacklisting logic] Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- v7->v8: * folded patch "watchdog: renesas_wdt: Blacklist early R-Car Gen2 SoCs" from Geert into this patch. Since Simon only reviewed Geert's patch, and Wolfram and Guenter only reviewed earlier versions of this patch, I am not including their "Reviewed-by" as they may disagree with the final result. Thanks, Fab drivers/watchdog/renesas_wdt.c | 49 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 5 deletions(-)