* [PATCH] PCI: PM: Fix ordering of operations in pci_back_from_sleep()
@ 2021-10-15 16:45 Rafael J. Wysocki
2021-10-20 14:24 ` Rafael J. Wysocki
2021-10-21 1:00 ` Bjorn Helgaas
0 siblings, 2 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2021-10-15 16:45 UTC (permalink / raw)
To: Linux PCI; +Cc: Linux PM, LKML, Bjorn Helgaas, Mika Westerberg
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ordering of operations in pci_back_from_sleep() is incorrect,
because the device may be in D3cold when it runs and pci_enable_wake()
needs to access the device's configuration space which cannot be
done in D3cold.
Fix this by calling pci_set_power_state() to put the device into D0
before calling pci_enable_wake() for it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/pci/pci.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -2638,8 +2638,13 @@ EXPORT_SYMBOL(pci_prepare_to_sleep);
*/
int pci_back_from_sleep(struct pci_dev *dev)
{
+ int ret = pci_set_power_state(dev, PCI_D0);
+
+ if (ret)
+ return ret;
+
pci_enable_wake(dev, PCI_D0, false);
- return pci_set_power_state(dev, PCI_D0);
+ return 0;
}
EXPORT_SYMBOL(pci_back_from_sleep);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] PCI: PM: Fix ordering of operations in pci_back_from_sleep()
2021-10-15 16:45 [PATCH] PCI: PM: Fix ordering of operations in pci_back_from_sleep() Rafael J. Wysocki
@ 2021-10-20 14:24 ` Rafael J. Wysocki
2021-10-21 1:00 ` Bjorn Helgaas
1 sibling, 0 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2021-10-20 14:24 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Linux PCI, Linux PM, LKML, Bjorn Helgaas, Mika Westerberg
On Fri, Oct 15, 2021 at 6:46 PM Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
>
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> The ordering of operations in pci_back_from_sleep() is incorrect,
> because the device may be in D3cold when it runs and pci_enable_wake()
> needs to access the device's configuration space which cannot be
> done in D3cold.
>
> Fix this by calling pci_set_power_state() to put the device into D0
> before calling pci_enable_wake() for it.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If there are no concerns about this one, I will queue it up for 5.16.
> ---
> drivers/pci/pci.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> Index: linux-pm/drivers/pci/pci.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci.c
> +++ linux-pm/drivers/pci/pci.c
> @@ -2638,8 +2638,13 @@ EXPORT_SYMBOL(pci_prepare_to_sleep);
> */
> int pci_back_from_sleep(struct pci_dev *dev)
> {
> + int ret = pci_set_power_state(dev, PCI_D0);
> +
> + if (ret)
> + return ret;
> +
> pci_enable_wake(dev, PCI_D0, false);
> - return pci_set_power_state(dev, PCI_D0);
> + return 0;
> }
> EXPORT_SYMBOL(pci_back_from_sleep);
>
>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] PCI: PM: Fix ordering of operations in pci_back_from_sleep()
2021-10-15 16:45 [PATCH] PCI: PM: Fix ordering of operations in pci_back_from_sleep() Rafael J. Wysocki
2021-10-20 14:24 ` Rafael J. Wysocki
@ 2021-10-21 1:00 ` Bjorn Helgaas
1 sibling, 0 replies; 3+ messages in thread
From: Bjorn Helgaas @ 2021-10-21 1:00 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: Linux PCI, Linux PM, LKML, Mika Westerberg
On Fri, Oct 15, 2021 at 06:45:59PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> The ordering of operations in pci_back_from_sleep() is incorrect,
> because the device may be in D3cold when it runs and pci_enable_wake()
> needs to access the device's configuration space which cannot be
> done in D3cold.
>
> Fix this by calling pci_set_power_state() to put the device into D0
> before calling pci_enable_wake() for it.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Thanks!
> ---
> drivers/pci/pci.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> Index: linux-pm/drivers/pci/pci.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci.c
> +++ linux-pm/drivers/pci/pci.c
> @@ -2638,8 +2638,13 @@ EXPORT_SYMBOL(pci_prepare_to_sleep);
> */
> int pci_back_from_sleep(struct pci_dev *dev)
> {
> + int ret = pci_set_power_state(dev, PCI_D0);
> +
> + if (ret)
> + return ret;
> +
> pci_enable_wake(dev, PCI_D0, false);
> - return pci_set_power_state(dev, PCI_D0);
> + return 0;
> }
> EXPORT_SYMBOL(pci_back_from_sleep);
>
>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-10-15 16:45 [PATCH] PCI: PM: Fix ordering of operations in pci_back_from_sleep() Rafael J. Wysocki
2021-10-20 14:24 ` Rafael J. Wysocki
2021-10-21 1:00 ` Bjorn Helgaas
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