[PATCH 5/6] drm/gma500: Rewrite power management code
Hans de Goede
hdegoede at redhat.com
Fri Sep 9 11:56:45 UTC 2022
Rewrite the power.c code. For some reason this was doing locking +
refcounting + state (suspended or not) bookkeeping all by itself.
But there is no reason for this, this is all taken care of by
the runtime-pm core, through pm_runtime_get()/_put().
Besides this not being necessary the DIY code is also quite weird/
buggy in some places. E.g. power_begin() would manually do a resume
when not resumed already and force_on=true, followed by a
pm_runtime_get(), which will cause a call to gma_power_resume() to
get scheduled which would redo the entire resume again. Which can
all be replaced by a single pm_runtime_get_sync() call.
Note that this is just a cleanup, this does not actually fix
the (disabled through #if 0) runtime-pm support. It does now call
pm_runtime_enable(), but only after doing a pm_runtime_get() at
probe-time, so the device is never runtime suspended.
Doing this permanent get() + enable() instead of not calling
enable() at all is necessary for the pm_runtime_get_if_in_use() call
in gma_power_begin() to work properly.
Note this also removes the gma_power_is_on() call a check like this
without actually holding a reference is always racy, so it is a bad
idea (and therefor has no pm_runtime_foo() equivalent).
The 2 code paths which were using gma_power_is_on() are actually both
guaranteed to only run when the device is powered-on so the 2 checks
can simply be dropped.
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
drivers/gpu/drm/gma500/oaktrail_lvds.c | 1 -
drivers/gpu/drm/gma500/power.c | 131 ++++++-------------------
drivers/gpu/drm/gma500/power.h | 9 --
drivers/gpu/drm/gma500/psb_drv.c | 6 --
drivers/gpu/drm/gma500/psb_drv.h | 4 +-
drivers/gpu/drm/gma500/psb_irq.c | 15 ++-
6 files changed, 37 insertions(+), 129 deletions(-)
diff --git a/drivers/gpu/drm/gma500/oaktrail_lvds.c b/drivers/gpu/drm/gma500/oaktrail_lvds.c
index 4d98df189e10..75b4eb1c8884 100644
--- a/drivers/gpu/drm/gma500/oaktrail_lvds.c
+++ b/drivers/gpu/drm/gma500/oaktrail_lvds.c
@@ -61,7 +61,6 @@ static void oaktrail_lvds_set_power(struct drm_device *dev,
pp_status = REG_READ(PP_STATUS);
} while (pp_status & PP_ON);
dev_priv->is_lvds_on = false;
- pm_request_idle(dev->dev);
}
gma_power_end(dev);
}
diff --git a/drivers/gpu/drm/gma500/power.c b/drivers/gpu/drm/gma500/power.c
index 66873085d450..5dd291dad4a4 100644
--- a/drivers/gpu/drm/gma500/power.c
+++ b/drivers/gpu/drm/gma500/power.c
@@ -37,9 +37,6 @@
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
-static struct mutex power_mutex; /* Serialize power ops */
-static DEFINE_SPINLOCK(power_ctrl_lock); /* Serialize power claim */
-
/**
* gma_power_init - initialise power manager
* @dev: our device
@@ -54,13 +51,22 @@ void gma_power_init(struct drm_device *dev)
dev_priv->apm_base = dev_priv->apm_reg & 0xffff;
dev_priv->ospm_base &= 0xffff;
- dev_priv->display_power = true; /* We start active */
- dev_priv->display_count = 0; /* Currently no users */
- dev_priv->suspended = false; /* And not suspended */
- mutex_init(&power_mutex);
-
if (dev_priv->ops->init_pm)
dev_priv->ops->init_pm(dev);
+
+ /*
+ * Runtime pm support is broken atm. So for now unconditionally
+ * call pm_runtime_get() here and put it again in psb_driver_unload()
+ *
+ * To fix this we need to call pm_runtime_get() once for each active
+ * pipe at boot and then put() / get() for each pipe disable / enable
+ * so that the device gets runtime suspended when no pipes are active.
+ */
+ pm_runtime_get(dev->dev);
+ pm_runtime_set_active(dev->dev); /* Must be done before pm_runtime_enable()! */
+ pm_runtime_enable(dev->dev);
+
+ dev_priv->pm_initialized = true;
}
/**
@@ -71,8 +77,13 @@ void gma_power_init(struct drm_device *dev)
*/
void gma_power_uninit(struct drm_device *dev)
{
+ struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
+
+ if (!dev_priv->pm_initialized)
+ return;
+
pm_runtime_disable(dev->dev);
- pm_runtime_set_suspended(dev->dev);
+ pm_runtime_put_noidle(dev->dev);
}
/**
@@ -85,11 +96,8 @@ static void gma_suspend_display(struct drm_device *dev)
{
struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
- if (dev_priv->suspended)
- return;
dev_priv->ops->save_regs(dev);
dev_priv->ops->power_down(dev);
- dev_priv->display_power = false;
}
/**
@@ -106,8 +114,6 @@ static void gma_resume_display(struct pci_dev *pdev)
/* turn on the display power island */
dev_priv->ops->power_up(dev);
- dev_priv->suspended = false;
- dev_priv->display_power = true;
PSB_WVDC32(dev_priv->pge_ctl | _PSB_PGETBL_ENABLED, PSB_PGETBL_CTL);
pci_write_config_word(pdev, PSB_GMCH_CTRL,
@@ -131,9 +137,6 @@ static void gma_suspend_pci(struct pci_dev *pdev)
struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
int bsm, vbt;
- if (dev_priv->suspended)
- return;
-
pci_save_state(pdev);
pci_read_config_dword(pdev, 0x5C, &bsm);
dev_priv->regs.saveBSM = bsm;
@@ -142,8 +145,6 @@ static void gma_suspend_pci(struct pci_dev *pdev)
pci_disable_device(pdev);
pci_set_power_state(pdev, PCI_D3hot);
-
- dev_priv->suspended = true;
}
/**
@@ -153,26 +154,17 @@ static void gma_suspend_pci(struct pci_dev *pdev)
* Perform the resume processing on our PCI device state - rewrite
* register state and re-enable the PCI device
*/
-static bool gma_resume_pci(struct pci_dev *pdev)
+static int gma_resume_pci(struct pci_dev *pdev)
{
struct drm_device *dev = pci_get_drvdata(pdev);
struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
- int ret;
-
- if (!dev_priv->suspended)
- return true;
pci_set_power_state(pdev, PCI_D0);
pci_restore_state(pdev);
pci_write_config_dword(pdev, 0x5c, dev_priv->regs.saveBSM);
pci_write_config_dword(pdev, 0xFC, dev_priv->regs.saveVBT);
- ret = pci_enable_device(pdev);
- if (ret != 0)
- dev_err(&pdev->dev, "pci_enable failed: %d\n", ret);
- else
- dev_priv->suspended = false;
- return !dev_priv->suspended;
+ return pci_enable_device(pdev);
}
/**
@@ -187,20 +179,10 @@ int gma_power_suspend(struct device *_dev)
{
struct pci_dev *pdev = to_pci_dev(_dev);
struct drm_device *dev = pci_get_drvdata(pdev);
- struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
- mutex_lock(&power_mutex);
- if (!dev_priv->suspended) {
- if (dev_priv->display_count) {
- mutex_unlock(&power_mutex);
- dev_err(dev->dev, "GPU hardware busy, cannot suspend\n");
- return -EBUSY;
- }
- gma_irq_uninstall(dev);
- gma_suspend_display(dev);
- gma_suspend_pci(pdev);
- }
- mutex_unlock(&power_mutex);
+ gma_irq_uninstall(dev);
+ gma_suspend_display(dev);
+ gma_suspend_pci(pdev);
return 0;
}
@@ -215,26 +197,12 @@ int gma_power_resume(struct device *_dev)
struct pci_dev *pdev = to_pci_dev(_dev);
struct drm_device *dev = pci_get_drvdata(pdev);
- mutex_lock(&power_mutex);
gma_resume_pci(pdev);
gma_resume_display(pdev);
gma_irq_install(dev);
- mutex_unlock(&power_mutex);
return 0;
}
-/**
- * gma_power_is_on - returne true if power is on
- * @dev: our DRM device
- *
- * Returns true if the display island power is on at this moment
- */
-bool gma_power_is_on(struct drm_device *dev)
-{
- struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
- return dev_priv->display_power;
-}
-
/**
* gma_power_begin - begin requiring power
* @dev: our DRM device
@@ -245,35 +213,10 @@ bool gma_power_is_on(struct drm_device *dev)
*/
bool gma_power_begin(struct drm_device *dev, bool force_on)
{
- struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
- struct pci_dev *pdev = to_pci_dev(dev->dev);
- int ret;
- unsigned long flags;
-
- spin_lock_irqsave(&power_ctrl_lock, flags);
- /* Power already on ? */
- if (dev_priv->display_power) {
- dev_priv->display_count++;
- pm_runtime_get(dev->dev);
- spin_unlock_irqrestore(&power_ctrl_lock, flags);
- return true;
- }
- if (force_on == false)
- goto out_false;
-
- /* Ok power up needed */
- ret = gma_resume_pci(pdev);
- if (ret == 0) {
- gma_irq_preinstall(dev);
- gma_irq_postinstall(dev);
- pm_runtime_get(dev->dev);
- dev_priv->display_count++;
- spin_unlock_irqrestore(&power_ctrl_lock, flags);
- return true;
- }
-out_false:
- spin_unlock_irqrestore(&power_ctrl_lock, flags);
- return false;
+ if (force_on)
+ return pm_runtime_resume_and_get(dev->dev) == 0;
+ else
+ return pm_runtime_get_if_in_use(dev->dev) == 1;
}
/**
@@ -285,12 +228,6 @@ bool gma_power_begin(struct drm_device *dev, bool force_on)
*/
void gma_power_end(struct drm_device *dev)
{
- struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
- unsigned long flags;
- spin_lock_irqsave(&power_ctrl_lock, flags);
- dev_priv->display_count--;
- WARN_ON(dev_priv->display_count < 0);
- spin_unlock_irqrestore(&power_ctrl_lock, flags);
pm_runtime_put(dev->dev);
}
@@ -304,16 +241,6 @@ int psb_runtime_resume(struct device *dev)
return gma_power_resume(dev);
}
-int psb_runtime_idle(struct device *dev)
-{
- struct drm_device *drmdev = pci_get_drvdata(to_pci_dev(dev));
- struct drm_psb_private *dev_priv = to_drm_psb_private(drmdev);
- if (dev_priv->display_count)
- return 0;
- else
- return 1;
-}
-
int gma_power_thaw(struct device *_dev)
{
return gma_power_resume(_dev);
diff --git a/drivers/gpu/drm/gma500/power.h b/drivers/gpu/drm/gma500/power.h
index 0c89c4d6ec20..243b9dd00910 100644
--- a/drivers/gpu/drm/gma500/power.h
+++ b/drivers/gpu/drm/gma500/power.h
@@ -54,19 +54,10 @@ int gma_power_restore(struct device *_dev);
bool gma_power_begin(struct drm_device *dev, bool force);
void gma_power_end(struct drm_device *dev);
-/*
- * Use this function to do an instantaneous check for if the hw is on.
- * Only use this in cases where you know the mutex is already held such
- * as in irq install/uninstall and you need to
- * prevent a deadlock situation. Otherwise use gma_power_begin().
- */
-bool gma_power_is_on(struct drm_device *dev);
-
/*
* GFX-Runtime PM callbacks
*/
int psb_runtime_suspend(struct device *dev);
int psb_runtime_resume(struct device *dev);
-int psb_runtime_idle(struct device *dev);
#endif /*_PSB_POWERMGMT_H_*/
diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index 8266371aeac1..aea8876059d8 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -407,11 +407,6 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags)
if (ret)
return ret;
psb_intel_opregion_enable_asle(dev);
-#if 0
- /* Enable runtime pm at last */
- pm_runtime_enable(dev->dev);
- pm_runtime_set_active(dev->dev);
-#endif
return devm_add_action_or_reset(dev->dev, psb_device_release, dev);
@@ -484,7 +479,6 @@ static const struct dev_pm_ops psb_pm_ops = {
.restore = gma_power_restore,
.runtime_suspend = psb_runtime_suspend,
.runtime_resume = psb_runtime_resume,
- .runtime_idle = psb_runtime_idle,
};
static const struct file_operations psb_gem_fops = {
diff --git a/drivers/gpu/drm/gma500/psb_drv.h b/drivers/gpu/drm/gma500/psb_drv.h
index dd6fd49d85f3..049701ce8a5f 100644
--- a/drivers/gpu/drm/gma500/psb_drv.h
+++ b/drivers/gpu/drm/gma500/psb_drv.h
@@ -426,9 +426,7 @@ struct drm_psb_private {
spinlock_t irqmask_lock;
/* Power */
- bool suspended;
- bool display_power;
- int display_count;
+ bool pm_initialized;
/* Modesetting */
struct psb_intel_mode_device mode_dev;
diff --git a/drivers/gpu/drm/gma500/psb_irq.c b/drivers/gpu/drm/gma500/psb_irq.c
index 038f18ed0a95..d421031462df 100644
--- a/drivers/gpu/drm/gma500/psb_irq.c
+++ b/drivers/gpu/drm/gma500/psb_irq.c
@@ -228,7 +228,7 @@ static irqreturn_t gma_irq_handler(int irq, void *arg)
vdc_stat &= dev_priv->vdc_irq_mask;
spin_unlock(&dev_priv->irqmask_lock);
- if (dsp_int && gma_power_is_on(dev)) {
+ if (dsp_int) {
gma_vdc_interrupt(dev, vdc_stat);
handled = 1;
}
@@ -264,13 +264,12 @@ void gma_irq_preinstall(struct drm_device *dev)
spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
- if (gma_power_is_on(dev)) {
- PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM);
- PSB_WVDC32(0x00000000, PSB_INT_MASK_R);
- PSB_WVDC32(0x00000000, PSB_INT_ENABLE_R);
- PSB_WSGX32(0x00000000, PSB_CR_EVENT_HOST_ENABLE);
- PSB_RSGX32(PSB_CR_EVENT_HOST_ENABLE);
- }
+ PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM);
+ PSB_WVDC32(0x00000000, PSB_INT_MASK_R);
+ PSB_WVDC32(0x00000000, PSB_INT_ENABLE_R);
+ PSB_WSGX32(0x00000000, PSB_CR_EVENT_HOST_ENABLE);
+ PSB_RSGX32(PSB_CR_EVENT_HOST_ENABLE);
+
if (dev->vblank[0].enabled)
dev_priv->vdc_irq_mask |= _PSB_VSYNC_PIPEA_FLAG;
if (dev->vblank[1].enabled)
--
2.37.2
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