| Message ID | 20200903112337.4113-8-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | acpi/pwm/i915: Convert pwm-crc and i915 driver's PWM code to use the atomic PWM API | expand |
On Thu, Sep 03, 2020 at 01:23:27PM +0200, Hans de Goede wrote: > PWM controller drivers should not restore the PWM state on resume. The > convention is that PWM consumers do this by calling pwm_apply_state(), > so that it can be done at the exact moment when the consumer needs > the state to be stored, avoiding e.g. backlight flickering. > > The only in kernel consumers of the pwm-lpss code, the i915 driver > and the pwm-class sysfs interface code both correctly restore the > state on resume, so there is no need to do this in the pwm-lpss code. > > More-over the removed resume handler is buggy, since it blindly > restores the ctrl-register contents without setting the update > bit, which is necessary to get the controller to actually use/apply > the restored base-unit and on-time-div values. While this is okay Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> the question is do we need to have similar in acpi_lpss.c? For example, static const struct lpss_device_desc byt_pwm_dev_desc = { .flags = LPSS_SAVE_CTX, ^^^^^^^^^^^^^^ .prv_offset = 0x800, .setup = byt_pwm_setup, }; static const struct lpss_device_desc bsw_pwm_dev_desc = { .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, ^^^^^^^^^^^^^^ .prv_offset = 0x800, .setup = bsw_pwm_setup, }; > Acked-by: Thierry Reding <thierry.reding@gmail.com> > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > Changes in v9: > - This is a new patch in v9 of this series > --- > drivers/pwm/pwm-lpss-platform.c | 1 - > drivers/pwm/pwm-lpss.c | 24 ------------------------ > drivers/pwm/pwm-lpss.h | 3 --- > 3 files changed, 28 deletions(-) > > diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c > index 48f34d20aecd..c6502cf7a7af 100644 > --- a/drivers/pwm/pwm-lpss-platform.c > +++ b/drivers/pwm/pwm-lpss-platform.c > @@ -89,7 +89,6 @@ static int pwm_lpss_prepare(struct device *dev) > > static const struct dev_pm_ops pwm_lpss_platform_pm_ops = { > .prepare = pwm_lpss_prepare, > - SET_SYSTEM_SLEEP_PM_OPS(pwm_lpss_suspend, pwm_lpss_resume) > }; > > static const struct acpi_device_id pwm_lpss_acpi_match[] = { > diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c > index 9c5c7217c9b6..3444c56b4bed 100644 > --- a/drivers/pwm/pwm-lpss.c > +++ b/drivers/pwm/pwm-lpss.c > @@ -260,30 +260,6 @@ int pwm_lpss_remove(struct pwm_lpss_chip *lpwm) > } > EXPORT_SYMBOL_GPL(pwm_lpss_remove); > > -int pwm_lpss_suspend(struct device *dev) > -{ > - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); > - int i; > - > - for (i = 0; i < lpwm->info->npwm; i++) > - lpwm->saved_ctrl[i] = readl(lpwm->regs + i * PWM_SIZE + PWM); > - > - return 0; > -} > -EXPORT_SYMBOL_GPL(pwm_lpss_suspend); > - > -int pwm_lpss_resume(struct device *dev) > -{ > - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); > - int i; > - > - for (i = 0; i < lpwm->info->npwm; i++) > - writel(lpwm->saved_ctrl[i], lpwm->regs + i * PWM_SIZE + PWM); > - > - return 0; > -} > -EXPORT_SYMBOL_GPL(pwm_lpss_resume); > - > MODULE_DESCRIPTION("PWM driver for Intel LPSS"); > MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>"); > MODULE_LICENSE("GPL v2"); > diff --git a/drivers/pwm/pwm-lpss.h b/drivers/pwm/pwm-lpss.h > index 7909fa12fca2..70db7e389d66 100644 > --- a/drivers/pwm/pwm-lpss.h > +++ b/drivers/pwm/pwm-lpss.h > @@ -19,7 +19,6 @@ struct pwm_lpss_chip { > struct pwm_chip chip; > void __iomem *regs; > const struct pwm_lpss_boardinfo *info; > - u32 saved_ctrl[MAX_PWMS]; > }; > > struct pwm_lpss_boardinfo { > @@ -37,7 +36,5 @@ struct pwm_lpss_boardinfo { > struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r, > const struct pwm_lpss_boardinfo *info); > int pwm_lpss_remove(struct pwm_lpss_chip *lpwm); > -int pwm_lpss_suspend(struct device *dev); > -int pwm_lpss_resume(struct device *dev); > > #endif /* __PWM_LPSS_H */ > -- > 2.28.0 >
On Thu, Sep 03, 2020 at 03:48:16PM +0300, Andy Shevchenko wrote: > On Thu, Sep 03, 2020 at 01:23:27PM +0200, Hans de Goede wrote: > the question is do we need to have similar in acpi_lpss.c? > For example, > static const struct lpss_device_desc byt_pwm_dev_desc = { > .flags = LPSS_SAVE_CTX, > ^^^^^^^^^^^^^^ > .prv_offset = 0x800, > .setup = byt_pwm_setup, > }; > > static const struct lpss_device_desc bsw_pwm_dev_desc = { > .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, > ^^^^^^^^^^^^^^ > .prv_offset = 0x800, > .setup = bsw_pwm_setup, > }; Okay, it's a private space which has clock and reset gating, so means we still need to handle it.
Hi, On 9/3/20 2:56 PM, Andy Shevchenko wrote: > On Thu, Sep 03, 2020 at 03:48:16PM +0300, Andy Shevchenko wrote: >> On Thu, Sep 03, 2020 at 01:23:27PM +0200, Hans de Goede wrote: > >> the question is do we need to have similar in acpi_lpss.c? >> For example, >> static const struct lpss_device_desc byt_pwm_dev_desc = { >> .flags = LPSS_SAVE_CTX, >> ^^^^^^^^^^^^^^ >> .prv_offset = 0x800, >> .setup = byt_pwm_setup, >> }; >> >> static const struct lpss_device_desc bsw_pwm_dev_desc = { >> .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, >> ^^^^^^^^^^^^^^ >> .prv_offset = 0x800, >> .setup = bsw_pwm_setup, >> }; > > Okay, it's a private space which has clock and reset gating, so means we still > need to handle it. Right I was about to say the same. As always, thank you for your reviews. Regards, Hans
diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c index 48f34d20aecd..c6502cf7a7af 100644 --- a/drivers/pwm/pwm-lpss-platform.c +++ b/drivers/pwm/pwm-lpss-platform.c @@ -89,7 +89,6 @@ static int pwm_lpss_prepare(struct device *dev) static const struct dev_pm_ops pwm_lpss_platform_pm_ops = { .prepare = pwm_lpss_prepare, - SET_SYSTEM_SLEEP_PM_OPS(pwm_lpss_suspend, pwm_lpss_resume) }; static const struct acpi_device_id pwm_lpss_acpi_match[] = { diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c index 9c5c7217c9b6..3444c56b4bed 100644 --- a/drivers/pwm/pwm-lpss.c +++ b/drivers/pwm/pwm-lpss.c @@ -260,30 +260,6 @@ int pwm_lpss_remove(struct pwm_lpss_chip *lpwm) } EXPORT_SYMBOL_GPL(pwm_lpss_remove); -int pwm_lpss_suspend(struct device *dev) -{ - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); - int i; - - for (i = 0; i < lpwm->info->npwm; i++) - lpwm->saved_ctrl[i] = readl(lpwm->regs + i * PWM_SIZE + PWM); - - return 0; -} -EXPORT_SYMBOL_GPL(pwm_lpss_suspend); - -int pwm_lpss_resume(struct device *dev) -{ - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); - int i; - - for (i = 0; i < lpwm->info->npwm; i++) - writel(lpwm->saved_ctrl[i], lpwm->regs + i * PWM_SIZE + PWM); - - return 0; -} -EXPORT_SYMBOL_GPL(pwm_lpss_resume); - MODULE_DESCRIPTION("PWM driver for Intel LPSS"); MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>"); MODULE_LICENSE("GPL v2"); diff --git a/drivers/pwm/pwm-lpss.h b/drivers/pwm/pwm-lpss.h index 7909fa12fca2..70db7e389d66 100644 --- a/drivers/pwm/pwm-lpss.h +++ b/drivers/pwm/pwm-lpss.h @@ -19,7 +19,6 @@ struct pwm_lpss_chip { struct pwm_chip chip; void __iomem *regs; const struct pwm_lpss_boardinfo *info; - u32 saved_ctrl[MAX_PWMS]; }; struct pwm_lpss_boardinfo { @@ -37,7 +36,5 @@ struct pwm_lpss_boardinfo { struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r, const struct pwm_lpss_boardinfo *info); int pwm_lpss_remove(struct pwm_lpss_chip *lpwm); -int pwm_lpss_suspend(struct device *dev); -int pwm_lpss_resume(struct device *dev); #endif /* __PWM_LPSS_H */