| Message ID | 57726196.5060909@free.fr (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Zhang Rui |
| Headers | show |
On Tue, Jun 28, 2016 at 01:37:58PM +0200, Mason wrote: > From: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> > > When this platform is suspended, firmware powers the entire SoC down, > except a few hardware blocks waiting for wakeup events. And there is > no context to save for this particular block. > > Therefore, there is nothing useful for the driver to do on suspend; > so we define a NULL suspend hook. On resume, the driver initializes > the block exactly as is done in the probe callback. > > Reviewed-by: Kevin Hilman <khilman@baylibre.com> > Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> > --- > Add Kevin's Reviewed-by tag. > Eduardo/Zhang, can you pick this patch up for 4.8? > --- > drivers/thermal/tango_thermal.c | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/drivers/thermal/tango_thermal.c b/drivers/thermal/tango_thermal.c > index 70e0d9f406e9..d571ce2f546d 100644 > --- a/drivers/thermal/tango_thermal.c > +++ b/drivers/thermal/tango_thermal.c > @@ -64,6 +64,12 @@ static const struct thermal_zone_of_device_ops ops = { > .get_temp = tango_get_temp, > }; > > +static void tango_thermal_init(struct tango_thermal_priv *priv) > +{ > + writel(0, priv->base + TEMPSI_CFG); > + writel(CMD_ON, priv->base + TEMPSI_CMD); > +} > + > static int tango_thermal_probe(struct platform_device *pdev) > { > struct resource *res; > @@ -79,14 +85,30 @@ static int tango_thermal_probe(struct platform_device *pdev) > if (IS_ERR(priv->base)) > return PTR_ERR(priv->base); > > + platform_set_drvdata(pdev, priv); > priv->thresh_idx = IDX_MIN; > - writel(0, priv->base + TEMPSI_CFG); > - writel(CMD_ON, priv->base + TEMPSI_CMD); > + tango_thermal_init(priv); > > tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &ops); > return PTR_ERR_OR_ZERO(tzdev); > } > > +#ifdef CONFIG_PM_SLEEP > +static int tango_thermal_resume(struct device *dev) > +{ > + struct tango_thermal_priv *priv = dev_get_drvdata(dev); > + tango_thermal_init(priv); checkpatch will warn about this. You're supposed to separate the local variable declarations and code by a single blank line. > + > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume); > + > +#define DEV_PM_OPS &tango_thermal_pm > +#else > +#define DEV_PM_OPS NULL > +#endif In my experience it's often not useful to #ifdef the struct pm_ops. These days you almost certainly want PM enabled, and the conditional doesn't save you all that much in the first place, because it's not unlikely for this to fit into some of the space that would be padded out anyway. As a side-note, I've noticed that this driver has the following dependencies: depends on ARCH_TANGO || COMPILE_TEST which, last I checked, is probably going to fail on some architectures because you need at least another one on HAS_IOMEM (for readl() and writel()). That's a pre-existing problem, of course, so should be fixed in a separate patch. Thierry
On Monday, July 18, 2016 11:33:28 AM CEST Thierry Reding wrote: > > + > > + return 0; > > +} > > + > > +static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume); > > + > > +#define DEV_PM_OPS &tango_thermal_pm > > +#else > > +#define DEV_PM_OPS NULL > > +#endif > > In my experience it's often not useful to #ifdef the struct pm_ops. > These days you almost certainly want PM enabled, and the conditional > doesn't save you all that much in the first place, because it's not > unlikely for this to fit into some of the space that would be padded > out anyway. This will also generate a warning when CONFIG_PM_SLEEP is not set. Better write this as #define DEV_PM_OPS (IS_ENABLED(CONFIG_PM_SLEEP) ? &tango_thermal_pm : NULL) so the compiler can drop the variable definition when it's not needed. > As a side-note, I've noticed that this driver has the following > dependencies: > > depends on ARCH_TANGO || COMPILE_TEST > > which, last I checked, is probably going to fail on some architectures > because you need at least another one on HAS_IOMEM (for readl() and > writel()). That's a pre-existing problem, of course, so should be fixed > in a separate patch. No need, we just merged a patch to no longer allow COMPILE_TEST on arch/um/, so we can safely rely on MMIO to be available for COMPILE_TEST. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jul 18, 2016 at 12:09:39PM +0200, Arnd Bergmann wrote: > On Monday, July 18, 2016 11:33:28 AM CEST Thierry Reding wrote: > > > > + > > > + return 0; > > > +} > > > + > > > +static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume); > > > + > > > +#define DEV_PM_OPS &tango_thermal_pm > > > +#else > > > +#define DEV_PM_OPS NULL > > > +#endif > > > > In my experience it's often not useful to #ifdef the struct pm_ops. > > These days you almost certainly want PM enabled, and the conditional > > doesn't save you all that much in the first place, because it's not > > unlikely for this to fit into some of the space that would be padded > > out anyway. > > This will also generate a warning when CONFIG_PM_SLEEP is not set. > Better write this as > > #define DEV_PM_OPS (IS_ENABLED(CONFIG_PM_SLEEP) ? &tango_thermal_pm : NULL) > > so the compiler can drop the variable definition when it's not > needed. My suggestion was to define tango_thermal_pm unconditionally to avoid any of these tricks. For any real use-case in which the 92 bytes for the struct dev_pm_ops would matter you most likely want PM_SLEEP anyway, so I don't really see why we would even want to make it optional. > > As a side-note, I've noticed that this driver has the following > > dependencies: > > > > depends on ARCH_TANGO || COMPILE_TEST > > > > which, last I checked, is probably going to fail on some architectures > > because you need at least another one on HAS_IOMEM (for readl() and > > writel()). That's a pre-existing problem, of course, so should be fixed > > in a separate patch. > > No need, we just merged a patch to no longer allow COMPILE_TEST on > arch/um/, so we can safely rely on MMIO to be available for COMPILE_TEST. I thought at least S390 didn't have readl() and writel() either, at least when PCI wasn't enabled, or some such. Thierry
On Monday, July 18, 2016 12:13:38 PM CEST Thierry Reding wrote: > On Mon, Jul 18, 2016 at 12:09:39PM +0200, Arnd Bergmann wrote: > > On Monday, July 18, 2016 11:33:28 AM CEST Thierry Reding wrote: > > > > > > + > > > > + return 0; > > > > +} > > > > + > > > > +static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume); > > > > + > > > > +#define DEV_PM_OPS &tango_thermal_pm > > > > +#else > > > > +#define DEV_PM_OPS NULL > > > > +#endif > > > > > > In my experience it's often not useful to #ifdef the struct pm_ops. > > > These days you almost certainly want PM enabled, and the conditional > > > doesn't save you all that much in the first place, because it's not > > > unlikely for this to fit into some of the space that would be padded > > > out anyway. > > > > This will also generate a warning when CONFIG_PM_SLEEP is not set. > > Better write this as > > > > #define DEV_PM_OPS (IS_ENABLED(CONFIG_PM_SLEEP) ? &tango_thermal_pm : NULL) > > > > so the compiler can drop the variable definition when it's not > > needed. > > My suggestion was to define tango_thermal_pm unconditionally to avoid > any of these tricks. For any real use-case in which the 92 bytes for the > struct dev_pm_ops would matter you most likely want PM_SLEEP anyway, so > I don't really see why we would even want to make it optional. Sure, leaving it unconditional works too. > > > As a side-note, I've noticed that this driver has the following > > > dependencies: > > > > > > depends on ARCH_TANGO || COMPILE_TEST > > > > > > which, last I checked, is probably going to fail on some architectures > > > because you need at least another one on HAS_IOMEM (for readl() and > > > writel()). That's a pre-existing problem, of course, so should be fixed > > > in a separate patch. > > > > No need, we just merged a patch to no longer allow COMPILE_TEST on > > arch/um/, so we can safely rely on MMIO to be available for COMPILE_TEST. > > I thought at least S390 didn't have readl() and writel() either, at > least when PCI wasn't enabled, or some such. Yes, but they've never complained about COMPILE_TEST breakage because of that. Tile is in the same boat too in some configurations. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jul 18, 2016 at 01:10:07PM +0200, Arnd Bergmann wrote: > On Monday, July 18, 2016 12:13:38 PM CEST Thierry Reding wrote: > > On Mon, Jul 18, 2016 at 12:09:39PM +0200, Arnd Bergmann wrote: > > > On Monday, July 18, 2016 11:33:28 AM CEST Thierry Reding wrote: > > > > > > > > + > > > > > + return 0; > > > > > +} > > > > > + > > > > > +static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume); > > > > > + > > > > > +#define DEV_PM_OPS &tango_thermal_pm > > > > > +#else > > > > > +#define DEV_PM_OPS NULL > > > > > +#endif > > > > > > > > In my experience it's often not useful to #ifdef the struct pm_ops. > > > > These days you almost certainly want PM enabled, and the conditional > > > > doesn't save you all that much in the first place, because it's not > > > > unlikely for this to fit into some of the space that would be padded > > > > out anyway. > > > > > > This will also generate a warning when CONFIG_PM_SLEEP is not set. > > > Better write this as > > > > > > #define DEV_PM_OPS (IS_ENABLED(CONFIG_PM_SLEEP) ? &tango_thermal_pm : NULL) > > > > > > so the compiler can drop the variable definition when it's not > > > needed. > > > > My suggestion was to define tango_thermal_pm unconditionally to avoid > > any of these tricks. For any real use-case in which the 92 bytes for the > > struct dev_pm_ops would matter you most likely want PM_SLEEP anyway, so > > I don't really see why we would even want to make it optional. > > Sure, leaving it unconditional works too. > > > > > As a side-note, I've noticed that this driver has the following > > > > dependencies: > > > > > > > > depends on ARCH_TANGO || COMPILE_TEST > > > > > > > > which, last I checked, is probably going to fail on some architectures > > > > because you need at least another one on HAS_IOMEM (for readl() and > > > > writel()). That's a pre-existing problem, of course, so should be fixed > > > > in a separate patch. > > > > > > No need, we just merged a patch to no longer allow COMPILE_TEST on > > > arch/um/, so we can safely rely on MMIO to be available for COMPILE_TEST. > > > > I thought at least S390 didn't have readl() and writel() either, at > > least when PCI wasn't enabled, or some such. > > Yes, but they've never complained about COMPILE_TEST breakage because > of that. Tile is in the same boat too in some configurations. Ah, okay. I remember running into this occasionally when doing randconfig builds on S390. That was many moons ago, so perhaps it's not an issue anymore, and maybe I've become overly cautious about the COMPILE_TEST dependency. Thierry
diff --git a/drivers/thermal/tango_thermal.c b/drivers/thermal/tango_thermal.c index 70e0d9f406e9..d571ce2f546d 100644 --- a/drivers/thermal/tango_thermal.c +++ b/drivers/thermal/tango_thermal.c @@ -64,6 +64,12 @@ static const struct thermal_zone_of_device_ops ops = { .get_temp = tango_get_temp, }; +static void tango_thermal_init(struct tango_thermal_priv *priv) +{ + writel(0, priv->base + TEMPSI_CFG); + writel(CMD_ON, priv->base + TEMPSI_CMD); +} + static int tango_thermal_probe(struct platform_device *pdev) { struct resource *res; @@ -79,14 +85,30 @@ static int tango_thermal_probe(struct platform_device *pdev) if (IS_ERR(priv->base)) return PTR_ERR(priv->base); + platform_set_drvdata(pdev, priv); priv->thresh_idx = IDX_MIN; - writel(0, priv->base + TEMPSI_CFG); - writel(CMD_ON, priv->base + TEMPSI_CMD); + tango_thermal_init(priv); tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &ops); return PTR_ERR_OR_ZERO(tzdev); } +#ifdef CONFIG_PM_SLEEP +static int tango_thermal_resume(struct device *dev) +{ + struct tango_thermal_priv *priv = dev_get_drvdata(dev); + tango_thermal_init(priv); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume); + +#define DEV_PM_OPS &tango_thermal_pm +#else +#define DEV_PM_OPS NULL +#endif + static const struct of_device_id tango_sensor_ids[] = { { .compatible = "sigma,smp8758-thermal", @@ -99,6 +121,7 @@ static struct platform_driver tango_thermal_driver = { .driver = { .name = "tango-thermal", .of_match_table = tango_sensor_ids, + .pm = DEV_PM_OPS, }, };