On Friday, 20 of June 2008, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@xxxxxxx>
>
> PCI PM: Rework device PM initialization
>
> Rework PCI device PM initialization so that if given device is capable
> of generating wake-up events, either natively through the PME#
> mechanism, or with the help of the platform, its power.can_wakeup
> and power.should_wakeup flags are set as appropriate.
>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
One correction is reqired in this patch. Namely, it's too early to call
pci_pm_init() in pci_scan_device(), because pci_device_add() will then call
device_initialize() and overwrite dev->dev.power settings.
Updated patch follows.
Thanks,
Rafael
---
From: Rafael J. Wysocki <rjw@xxxxxxx>
PCI PM: Rework device PM initialization (rev. 2)
Rework PCI device PM initialization so that if given device is capable
of generating wake-up events, either natively through the PME#
mechanism, or with the help of the platform, its power.can_wakeup
and power.should_wakeup flags are set as appropriate.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/pci/pci.c | 145 ++++++++++++++++++++++++++++++++--------------------
drivers/pci/pci.h | 1
drivers/pci/probe.c | 47 +---------------
3 files changed, 95 insertions(+), 98 deletions(-)
Index: linux-next/drivers/pci/pci.c
===================================================================
--- linux-next.orig/drivers/pci/pci.c
+++ linux-next/drivers/pci/pci.c
@@ -1016,6 +1016,53 @@ int pci_set_pcie_reset_state(struct pci_
}
/**
+ * pci_pme_capable - check the capability of PCI device to generate PME#
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @state: PCI state from which device will issue PME#.
+ */
+static bool pci_pme_capable(struct pci_dev *dev, int pm, pci_power_t state)
+{
+ u16 pmc;
+
+ if (!pm)
+ return false;
+
+ /* Check device's ability to generate PME# from given state */
+ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
+
+ pmc &= PCI_PM_CAP_PME_MASK;
+ pmc >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
+
+ return !!(pmc & (1 << state));
+}
+
+/**
+ * pci_pme_active - enable or disable PCI device's PME# function
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @enable: 'true' to enable PME# generation; 'false' to disable it.
+ *
+ * The caller must verify that the device is capable of generating PME# before
+ * calling this function with @enable equal to 'true'.
+ */
+static void pci_pme_active(struct pci_dev *dev, int pm, bool enable)
+{
+ u16 pmcsr;
+
+ if (!pm)
+ return;
+
+ pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ /* Clear PME_Status by writing 1 to it and enable PME# */
+ pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
+ if (!enable)
+ pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
+
+ pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
+}
+
+/**
* pci_enable_wake - enable PCI device as wakeup event source
* @dev: PCI device affected
* @state: PCI state from which device will issue wakeup events
@@ -1030,77 +1077,67 @@ int pci_set_pcie_reset_state(struct pci_
* supporting the standard PCI PME# signal may require such platform hooks;
* they always update bits in config space to allow PME# generation.
*
- * -EIO is returned if the device can't be a wakeup event source.
- * -EINVAL is returned if the device can't generate wakeup events from
- * the specified PCI state. Returns zero if the operation is successful.
+ * RETURN VALUE:
+ * 0 is returned on success
+ * -EINVAL is returned if device is not supposed to wake up the system
+ * Error code depending on the platform is returned if both the platform and the
+ * native mechanism fail to enable the generation of wake-up events
*/
int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
{
int pm;
- u16 value = 0;
- bool platform_done = false;
+ int error = 0;
- if (enable && platform_pci_can_wakeup(dev)) {
- /* Allow the platform to handle the device */
- int err = platform_pci_sleep_wake(dev, true);
- if (!err)
- /*
- * The platform claims to have enabled the device's
- * system wake-up capability as requested, but we are
- * going to enable PME# anyway.
- */
- platform_done = true;
- }
+ if (!device_may_wakeup(&dev->dev))
+ return -EINVAL;
- /* find PCI PM capability in list */
- pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+ if (enable && platform_pci_can_wakeup(dev))
+ error = platform_pci_sleep_wake(dev, true);
- /* If device doesn't support PM Capabilities, but caller wants to
- * disable wake events, it's a NOP. Otherwise fail unless the
- * platform hooks handled this legacy device already.
+ /*
+ * We are going to enable/disable the generation of PME# even if the
+ * platform claims to have handled the device as requested.
*/
- if (!pm) {
+ pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+ if (!enable || pci_pme_capable(dev, pm, state)) {
+ pci_pme_active(dev, pm, enable);
if (enable)
- return platform_done ? 0 : -EIO;
- else
- goto Platform_disable;
- }
-
- /* Check device's ability to generate PME# */
- pci_read_config_word(dev, pm + PCI_PM_PMC, &value);
-
- value &= PCI_PM_CAP_PME_MASK;
- value >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
-
- /* Check if it can generate PME# from requested state. */
- if (!value || !(value & (1 << state))) {
- if (enable) {
- return platform_done ? 0 : -EINVAL;
- } else {
- value = 0;
- goto Platform_disable;
- }
+ return 0;
}
- pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
+ if (!enable && platform_pci_can_wakeup(dev))
+ error = platform_pci_sleep_wake(dev, false);
- /* Clear PME_Status by writing 1 to it and enable PME# */
- value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
+ return error;
+}
- if (!enable)
- value &= ~PCI_PM_CTRL_PME_ENABLE;
+/**
+ * pci_pm_init - Initialize PM functions of given PCI device
+ * @dev: PCI device to handle.
+ */
+void pci_pm_init(struct pci_dev *dev)
+{
+ int pm;
+ bool can_wakeup = false;
- pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
+ /* find PCI PM capability in list */
+ pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+ if (pm) {
+ u16 pmc;
- Platform_disable:
- if (!enable && platform_pci_can_wakeup(dev)) {
- /* Allow the platform to finalize the operation */
- int err = platform_pci_sleep_wake(dev, false);
- if (err && !value)
- return -EIO;
+ /* Check device's ability to generate PME# */
+ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
+ if (pmc & PCI_PM_CAP_PME_MASK) {
+ can_wakeup = true;
+ /* Disable the PME# generation capability */
+ pci_pme_active(dev, pm, false);
+ }
}
- return 0;
+ if (platform_pci_can_wakeup(dev))
+ can_wakeup = true;
+
+ device_init_wakeup(&dev->dev, can_wakeup);
}
int
Index: linux-next/drivers/pci/pci.h
===================================================================
--- linux-next.orig/drivers/pci/pci.h
+++ linux-next/drivers/pci/pci.h
@@ -35,6 +35,7 @@ struct pci_platform_pm_ops {
};
extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops);
+extern void pci_pm_init(struct pci_dev *dev);
extern int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val);
extern int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val);
Index: linux-next/drivers/pci/probe.c
===================================================================
--- linux-next.orig/drivers/pci/probe.c
+++ linux-next/drivers/pci/probe.c
@@ -858,49 +858,6 @@ int pci_cfg_space_size_ext(struct pci_de
return PCI_CFG_SPACE_SIZE;
}
-/**
- * pci_disable_pme - Disable the PME function of PCI device
- * @dev: PCI device affected
- * -EINVAL is returned if PCI device doesn't support PME.
- * Zero is returned if the PME is supported and can be disabled.
- */
-static int pci_disable_pme(struct pci_dev *dev)
-{
- int pm;
- u16 value;
-
- /* find PCI PM capability in list */
- pm = pci_find_capability(dev, PCI_CAP_ID_PM);
-
- /* If device doesn't support PM Capabilities, it means that PME is
- * not supported.
- */
- if (!pm)
- return -EINVAL;
- /* Check device's ability to generate PME# */
- pci_read_config_word(dev, pm + PCI_PM_PMC, &value);
-
- value &= PCI_PM_CAP_PME_MASK;
- /* Check if it can generate PME# */
- if (!value) {
- /*
- * If it is zero, it means that PME is still unsupported
- * although there exists the PM capability.
- */
- return -EINVAL;
- }
-
- pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
-
- /* Clear PME_Status by writing 1 to it */
- value |= PCI_PM_CTRL_PME_STATUS ;
- /* Disable PME enable bit */
- value &= ~PCI_PM_CTRL_PME_ENABLE;
- pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
-
- return 0;
-}
-
int pci_cfg_space_size(struct pci_dev *dev)
{
int pos;
@@ -1008,7 +965,6 @@ static struct pci_dev *pci_scan_device(s
}
pci_vpd_pci22_init(dev);
- pci_disable_pme(dev);
return dev;
}
@@ -1029,6 +985,9 @@ void pci_device_add(struct pci_dev *dev,
/* Fix up broken headers */
pci_fixup_device(pci_fixup_header, dev);
+ /* Initialize power management of the device */
+ pci_pm_init(dev);
+
/*
* Add the device to our list of discovered devices
* and the bus list for fixup functions, etc.
--
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