* [PATCH v2 1/2] PCI/PM: refactor pci_pm_suspend_noirq()
@ 2022-07-14 23:16 Rajvi Jingar
2022-07-14 23:16 ` [PATCH v2 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled Rajvi Jingar
0 siblings, 1 reply; 3+ messages in thread
From: Rajvi Jingar @ 2022-07-14 23:16 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
---
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 v2 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled
2022-07-14 23:16 [PATCH v2 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rajvi Jingar
@ 2022-07-14 23:16 ` Rajvi Jingar
2022-07-15 11:46 ` Rafael J. Wysocki
0 siblings, 1 reply; 3+ messages in thread
From: Rajvi Jingar @ 2022-07-14 23:16 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.
Also, perform ptm_enabled check in pci_ptm_disable() to avoid config
space access in case if PTM is already disabled for the device.
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
---
v1->v2:
- add ptm_enabled check in pci_ptm_disable().
- set the dev->ptm_enabled value in pci_restore_ptm_state().
---
drivers/pci/pcie/ptm.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index 368a254e3124..8dc7d2285a0d 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -34,6 +34,9 @@ void pci_disable_ptm(struct pci_dev *dev)
int ptm;
u16 ctrl;
+ if (!dev->ptm_enabled)
+ return;
+
if (!pci_is_pcie(dev))
return;
@@ -44,6 +47,7 @@ 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 +87,7 @@ 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 v2 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled
2022-07-14 23:16 ` [PATCH v2 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled Rajvi Jingar
@ 2022-07-15 11:46 ` Rafael J. Wysocki
0 siblings, 0 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2022-07-15 11:46 UTC (permalink / raw)
To: Rajvi Jingar
Cc: Rafael Wysocki, Bjorn Helgaas, David Box, Linux PCI,
Linux Kernel Mailing List, Linux PM
On Fri, Jul 15, 2022 at 1:16 AM Rajvi Jingar
<rajvi.jingar@linux.intel.com> wrote:
>
> 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.
>
> Also, perform ptm_enabled check in pci_ptm_disable() to avoid config
> space access in case if PTM is already disabled for the device.
>
> Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> ---
> v1->v2:
> - add ptm_enabled check in pci_ptm_disable().
> - set the dev->ptm_enabled value in pci_restore_ptm_state().
> ---
> drivers/pci/pcie/ptm.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
> index 368a254e3124..8dc7d2285a0d 100644
> --- a/drivers/pci/pcie/ptm.c
> +++ b/drivers/pci/pcie/ptm.c
> @@ -34,6 +34,9 @@ void pci_disable_ptm(struct pci_dev *dev)
> int ptm;
> u16 ctrl;
>
> + if (!dev->ptm_enabled)
> + return;
> +
> if (!pci_is_pcie(dev))
> return;
After the check you've added this doesn't need to be checked any more,
because ptm_enabled will not be set if pci_is_pcie(dev) is not true
AFAICS.
Otherwise the patch looks good to me, so with the above addressed,
please feel free to add
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
to it.
Thanks!
>
> @@ -44,6 +47,7 @@ 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 +87,7 @@ 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 [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-07-15 11:47 UTC | newest]
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2022-07-14 23:16 [PATCH v2 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rajvi Jingar
2022-07-14 23:16 ` [PATCH v2 2/2] PCI/PTM: fix to maintain pci_dev->ptm_enabled Rajvi Jingar
2022-07-15 11:46 ` Rafael J. Wysocki
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