* Re: [PATCH 1/2] PCI/PM: refactor pci_pm_suspend_noirq()
[not found] <20220224202937.2414867-1-rajvi.jingar@intel.com>
@ 2022-03-11 18:33 ` Rafael J. Wysocki
0 siblings, 0 replies; 5+ messages in thread
From: Rafael J. Wysocki @ 2022-03-11 18:33 UTC (permalink / raw
To: Rajvi Jingar, bhelgaas; +Cc: david.e.box, linux-pci, linux-kernel
On 2/24/2022 9:29 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>
> ---
> drivers/pci/pci-driver.c | 15 ++-------------
> 1 file changed, 2 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 588588cfda48..ac3f7e1676a9 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -834,20 +834,9 @@ static int pci_pm_suspend_noirq(struct device *dev)
> }
> }
>
> - if (pci_dev->skip_bus_pm) {
> - /*
> - * 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.
> - */
The comment is outdated, but the role of skip_bus_pm needs to be
explained. It only applies to the bridge with a child in D0 case now,
because the other one has gone away, so I would put a new comment before
the reworked check below.
> - if (!pci_dev->state_saved)
> - pci_save_state(pci_dev);
> - } else if (!pci_dev->state_saved) {
> + if (!pci_dev->state_saved) {
> pci_save_state(pci_dev);
> - if (pci_power_manageable(pci_dev))
For example:
/*
* 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->skip_bus_pm && pci_power_manageable(pci_dev))
> pci_prepare_to_sleep(pci_dev);
> }
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] PCI/PM: refactor pci_pm_suspend_noirq()
@ 2022-07-07 17:22 Rajvi Jingar
2022-07-07 17:22 ` [PATCH 2/2] PCI/PTM: fix in pci_disable_ptm() Rajvi Jingar
0 siblings, 1 reply; 5+ messages in thread
From: Rajvi Jingar @ 2022-07-07 17:22 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>
---
This patch is a resend of https://lkml.org/lkml/2022/6/8/1462
---
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] 5+ messages in thread
* [PATCH 2/2] PCI/PTM: fix in pci_disable_ptm()
2022-07-07 17:22 [PATCH 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rajvi Jingar
@ 2022-07-07 17:22 ` Rajvi Jingar
2022-07-07 18:27 ` Rafael J. Wysocki
0 siblings, 1 reply; 5+ messages in thread
From: Rajvi Jingar @ 2022-07-07 17:22 UTC (permalink / raw
To: rafael.j.wysocki, bhelgaas
Cc: rajvi.jingar, david.e.box, linux-pci, linux-kernel, linux-pm
Set ptm_enabled from 'struct pci_dev' to 0 in pci_ptm_disable() to
save the disabled PTM state for the device.
Fixes: a697f072f5da ("PCI: Disable PTM during suspend to save power")
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
---
drivers/pci/pcie/ptm.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
index 368a254e3124..746e29779c27 100644
--- a/drivers/pci/pcie/ptm.c
+++ b/drivers/pci/pcie/ptm.c
@@ -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)
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] PCI/PTM: fix in pci_disable_ptm()
2022-07-07 17:22 ` [PATCH 2/2] PCI/PTM: fix in pci_disable_ptm() Rajvi Jingar
@ 2022-07-07 18:27 ` Rafael J. Wysocki
2022-07-07 18:32 ` Rafael J. Wysocki
0 siblings, 1 reply; 5+ messages in thread
From: Rafael J. Wysocki @ 2022-07-07 18:27 UTC (permalink / raw
To: Rajvi Jingar
Cc: Rafael Wysocki, Bjorn Helgaas, David Box, Linux PCI,
Linux Kernel Mailing List, Linux PM
On Thu, Jul 7, 2022 at 7:22 PM Rajvi Jingar
<rajvi.jingar@linux.intel.com> wrote:
>
> Set ptm_enabled from 'struct pci_dev' to 0 in pci_ptm_disable() to
I would set "Clear" here instead of "Set", but moreover ->
> save the disabled PTM state for the device.
>
> Fixes: a697f072f5da ("PCI: Disable PTM during suspend to save power")
> Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> ---
> drivers/pci/pcie/ptm.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
> index 368a254e3124..746e29779c27 100644
> --- a/drivers/pci/pcie/ptm.c
> +++ b/drivers/pci/pcie/ptm.c
> @@ -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;
-> I don't think that this is going to work without setting
dev->ptm_enabled in pci_restore_ptm_state() if the restored state
turns out to be "enabled".
> }
>
> void pci_save_ptm_state(struct pci_dev *dev)
> --
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] PCI/PTM: fix in pci_disable_ptm()
2022-07-07 18:27 ` Rafael J. Wysocki
@ 2022-07-07 18:32 ` Rafael J. Wysocki
0 siblings, 0 replies; 5+ messages in thread
From: Rafael J. Wysocki @ 2022-07-07 18:32 UTC (permalink / raw
To: Rajvi Jingar
Cc: Bjorn Helgaas, David Box, Linux PCI, Linux Kernel Mailing List,
Linux PM
On Thu, Jul 7, 2022 at 8:27 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Thu, Jul 7, 2022 at 7:22 PM Rajvi Jingar
> <rajvi.jingar@linux.intel.com> wrote:
> >
> > Set ptm_enabled from 'struct pci_dev' to 0 in pci_ptm_disable() to
>
> I would set "Clear" here instead of "Set", but moreover ->
s/set/say/ sorry.
> > save the disabled PTM state for the device.
> >
> > Fixes: a697f072f5da ("PCI: Disable PTM during suspend to save power")
> > Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
> > ---
> > drivers/pci/pcie/ptm.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c
> > index 368a254e3124..746e29779c27 100644
> > --- a/drivers/pci/pcie/ptm.c
> > +++ b/drivers/pci/pcie/ptm.c
> > @@ -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;
>
> -> I don't think that this is going to work without setting
> dev->ptm_enabled in pci_restore_ptm_state() if the restored state
> turns out to be "enabled".
And arguably, this function doesn't need to do anything if
dev->ptm_enabled is 0 already and this is the only check it needs to
do, because dev->ptm_enabled will only be set for PCIe devices that
have PTM.
> > }
> >
> > void pci_save_ptm_state(struct pci_dev *dev)
> > --
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-07-07 18:34 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2022-07-07 17:22 [PATCH 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rajvi Jingar
2022-07-07 17:22 ` [PATCH 2/2] PCI/PTM: fix in pci_disable_ptm() Rajvi Jingar
2022-07-07 18:27 ` Rafael J. Wysocki
2022-07-07 18:32 ` Rafael J. Wysocki
[not found] <20220224202937.2414867-1-rajvi.jingar@intel.com>
2022-03-11 18:33 ` [PATCH 1/2] PCI/PM: refactor pci_pm_suspend_noirq() Rafael J. Wysocki
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