* [PATCH v3 1/2] PCI/PM: refactor pci_pm_suspend_noirq()
@ 2022-07-15 18:18 Rajvi Jingar
2022-07-15 18:18 ` [PATCH v3 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled Rajvi Jingar
0 siblings, 1 reply; 3+ messages in thread
From: Rajvi Jingar @ 2022-07-15 18:18 UTC (permalink / raw)
To: rafael.j.wysocki, bhelgaas
Cc: rajvi.jingar, david.e.box, linux-pci, linux-kernel, linux-pm
The state of the device is saved during pci_pm_suspend_noirq(), if it
has not already been saved, regardless of the skip_bus_pm flag value. So
skip_bus_pm check is removed before saving the device state.
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
v1->v2: no change
v2->v3: no change
---
drivers/pci/pci-driver.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 49238ddd39ee..1f64de3e5280 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -867,20 +867,14 @@ static int pci_pm_suspend_noirq(struct device *dev)
}
}
- if (pci_dev->skip_bus_pm) {
+ if (!pci_dev->state_saved) {
+ pci_save_state(pci_dev);
/*
- * Either the device is a bridge with a child in D0 below it, or
- * the function is running for the second time in a row without
- * going through full resume, which is possible only during
- * suspend-to-idle in a spurious wakeup case. The device should
- * be in D0 at this point, but if it is a bridge, it may be
- * necessary to save its state.
+ * If the device is a bridge with a child in D0 below it, it needs to
+ * stay in D0, so check skip_bus_pm to avoid putting it into a
+ * low-power state in that case.
*/
- if (!pci_dev->state_saved)
- pci_save_state(pci_dev);
- } else if (!pci_dev->state_saved) {
- pci_save_state(pci_dev);
- if (pci_power_manageable(pci_dev))
+ if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
pci_prepare_to_sleep(pci_dev);
}
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v3 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled
2022-07-15 18:18 [PATCH v3 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rajvi Jingar
@ 2022-07-15 18:18 ` Rajvi Jingar
0 siblings, 0 replies; 3+ messages in thread
From: Rajvi Jingar @ 2022-07-15 18:18 UTC (permalink / raw)
To: rafael.j.wysocki, bhelgaas
Cc: rajvi.jingar, david.e.box, linux-pci, linux-kernel, linux-pm
pci_dev->ptm_enabled needs to be maintained to reflect the current PTM
state of the device. In pci_ptm_disable(), clear ptm_enabled from
'struct pci_dev' on disabling PTM state for the device.
In pci_restore_ptm_state(), set dev->ptm_enabled based on the restored
PTM state of the device.
In pci_ptm_disable(), perform ptm_enabled check to avoid config space
access in case if PTM is already disabled for the device. ptm_enabled
won't be set for non-PCIe devices so pci_is_pcie(dev) check is not
needed anymore.
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
v1->v2:
- add ptm_enabled check in pci_ptm_disable().
- set the dev->ptm_enabled value in pci_restore_ptm_state().
v2->v3:
- remove pci_is_pcie(dev) check in pci_ptm_disable().
- add Reviewed-by tag in commit message
---
drivers/pci/pcie/ptm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index 368a254e3124..1ce241d4538f 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -34,7 +34,7 @@ void pci_disable_ptm(struct pci_dev *dev)
int ptm;
u16 ctrl;
- if (!pci_is_pcie(dev))
+ if (!dev->ptm_enabled)
return;
ptm = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM);
@@ -44,6 +44,7 @@ void pci_disable_ptm(struct pci_dev *dev)
pci_read_config_word(dev, ptm + PCI_PTM_CTRL, &ctrl);
ctrl &= ~(PCI_PTM_CTRL_ENABLE | PCI_PTM_CTRL_ROOT);
pci_write_config_word(dev, ptm + PCI_PTM_CTRL, ctrl);
+ dev->ptm_enabled = 0;
}
void pci_save_ptm_state(struct pci_dev *dev)
@@ -83,6 +84,7 @@ void pci_restore_ptm_state(struct pci_dev *dev)
cap = (u16 *)&save_state->cap.data[0];
pci_write_config_word(dev, ptm + PCI_PTM_CTRL, *cap);
+ dev->ptm_enabled = !!(*cap & PCI_PTM_CTRL_ENABLE);
}
void pci_ptm_init(struct pci_dev *dev)
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v3 1/2] PCI/PM: refactor pci_pm_suspend_noirq()
[not found] <20220318221932.3305691-1-rajvi.jingar@intel.com>
@ 2022-03-25 16:56 ` Rafael J. Wysocki
0 siblings, 0 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2022-03-25 16:56 UTC (permalink / raw)
To: Rajvi Jingar, bhelgaas; +Cc: david.e.box, linux-pci, linux-kernel, linux-pm
On 3/18/2022 11:19 PM, Rajvi Jingar wrote:
> The state of the device is saved during pci_pm_suspend_noirq(), if it
> has not already been saved, regardless of the skip_bus_pm flag value. So
> skip_bus_pm check is removed before saving the device state.
>
> Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
> Suggested-by: David E. Box <david.e.box@linux.intel.com>
> ---
> v1 -> v2: add comments to the changes
> v2 -> v3: move changelog after "---" marker
And you need to add one more "---" marker right after it.
Analogously in the second patch.
> drivers/pci/pci-driver.c | 18 ++++++------------
> 1 file changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 588588cfda48..ffe76f238d7e 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -834,20 +834,14 @@ static int pci_pm_suspend_noirq(struct device *dev)
> }
> }
>
> - if (pci_dev->skip_bus_pm) {
> + if (!pci_dev->state_saved) {
> + pci_save_state(pci_dev);
> /*
> - * Either the device is a bridge with a child in D0 below it, or
> - * the function is running for the second time in a row without
> - * going through full resume, which is possible only during
> - * suspend-to-idle in a spurious wakeup case. The device should
> - * be in D0 at this point, but if it is a bridge, it may be
> - * necessary to save its state.
> + * If the device is a bridge with a child in D0 below it, it needs to
> + * stay in D0, so check skip_bus_pm to avoid putting it into a
> + * low-power state in that case.
> */
> - if (!pci_dev->state_saved)
> - pci_save_state(pci_dev);
> - } else if (!pci_dev->state_saved) {
> - pci_save_state(pci_dev);
> - if (pci_power_manageable(pci_dev))
> + if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
> pci_prepare_to_sleep(pci_dev);
> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-07-15 18:18 [PATCH v3 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rajvi Jingar
2022-07-15 18:18 ` [PATCH v3 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled Rajvi Jingar
[not found] <20220318221932.3305691-1-rajvi.jingar@intel.com>
2022-03-25 16:56 ` [PATCH v3 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rafael J. Wysocki
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