From: Hans de Goede <hdegoede@redhat.com>
To: "Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Jani Nikula" <jani.nikula@linux.intel.com>,
"Joonas Lahtinen" <joonas.lahtinen@linux.intel.com>,
"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
"Ville Syrjälä" <ville.syrjala@linux.intel.com>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
"Len Brown" <lenb@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>,
linux-pwm@vger.kernel.org,
intel-gfx <intel-gfx@lists.freedesktop.org>,
dri-devel@lists.freedesktop.org,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
linux-acpi@vger.kernel.org
Subject: [PATCH v9 07/17] pwm: lpss: Remove suspend/resume handlers
Date: Thu, 3 Sep 2020 12:51:04 +0200 [thread overview]
Message-ID: <20200903105114.9969-8-hdegoede@redhat.com> (raw)
In-Reply-To: <20200903105114.9969-1-hdegoede@redhat.com>
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.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
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
next prev parent reply other threads:[~2020-09-03 10:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 10:50 [PATCH v9 00/17] acpi/pwm/i915: Convert pwm-crc and i915 driver's PWM code to use the atomic PWM API Hans de Goede
2020-09-03 10:50 ` [PATCH v9 01/17] ACPI / LPSS: Resume Cherry Trail PWM controller in no-irq phase Hans de Goede
2020-09-03 10:50 ` [PATCH v9 02/17] ACPI / LPSS: Save Cherry Trail PWM ctx registers only once (at activation) Hans de Goede
2020-09-03 10:51 ` [PATCH v9 03/17] pwm: lpss: Fix off by one error in base_unit math in pwm_lpss_prepare() Hans de Goede
2020-09-03 10:51 ` [PATCH v9 04/17] pwm: lpss: Add range limit check for the base_unit register value Hans de Goede
2020-09-03 10:51 ` [PATCH v9 05/17] pwm: lpss: Add pwm_lpss_prepare_enable() helper Hans de Goede
2020-09-03 10:51 ` [PATCH v9 06/17] pwm: lpss: Make pwm_lpss_apply() not rely on existing hardware state Hans de Goede
2020-09-03 10:59 ` Thierry Reding
2020-09-03 11:12 ` Hans de Goede
2020-09-03 10:51 ` Hans de Goede [this message]
2020-09-03 11:00 ` [PATCH v9 07/17] pwm: lpss: Remove suspend/resume handlers Thierry Reding
2020-09-03 10:51 ` [PATCH v9 08/17] pwm: crc: Fix period / duty_cycle times being off by a factor of 256 Hans de Goede
2020-09-03 10:51 ` [PATCH v9 09/17] pwm: crc: Fix off-by-one error in the clock-divider calculations Hans de Goede
2020-09-03 10:51 ` [PATCH v9 10/17] pwm: crc: Fix period changes not having any effect Hans de Goede
2020-09-03 10:51 ` [PATCH v9 11/17] pwm: crc: Enable/disable PWM output on enable/disable Hans de Goede
2020-09-03 10:51 ` [PATCH v9 12/17] pwm: crc: Implement apply() method to support the new atomic PWM API Hans de Goede
2020-09-03 10:51 ` [PATCH v9 13/17] pwm: crc: Implement get_state() method Hans de Goede
2020-09-03 10:51 ` [PATCH v9 14/17] drm/i915: panel: Add get_vbt_pwm_freq() helper Hans de Goede
2020-09-03 10:51 ` [PATCH v9 15/17] drm/i915: panel: Honor the VBT PWM frequency for devs with an external PWM controller Hans de Goede
2020-09-03 10:51 ` [PATCH v9 16/17] drm/i915: panel: Honor the VBT PWM min setting " Hans de Goede
2020-09-03 10:51 ` [PATCH v9 17/17] drm/i915: panel: Use atomic PWM API " Hans de Goede
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