* Re: [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM
2025-06-11 23:31 [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM Mario Limonciello
@ 2025-06-12 0:40 ` Sathyanarayanan Kuppuswamy
2025-06-12 7:01 ` Nicolas Dichtel
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Sathyanarayanan Kuppuswamy @ 2025-06-12 0:40 UTC (permalink / raw)
To: Mario Limonciello, mario.limonciello, bhelgaas, rafael
Cc: Alex Williamson, Giovanni Cabiddu, Nicolas Dichtel, linux-pci
On 6/11/25 4:31 PM, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> commit 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when
> initializing") intended to put PCI devices into D0, but in doing so
> unintentionally changed runtime PM initialization not to occur on
> devices that don't support PCI PM. This caused a regression in vfio-pci
> due to an imbalance with it's use.
>
> Adjust the logic in pci_pm_init() so that even if PCI PM isn't supported
> runtime PM is still initialized.
>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m7e8929d6421690dc8bd6dc639d86c2b4db27cbc4
> Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m40d277dcdb9be64a1609a82412d1aa906263e201
> Tested-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Fixes: 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
Looks fine to me.
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> v2:
> * remove pointless return
> ---
> drivers/pci/pci.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 3dd44d1ad829b..160a9a482c732 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3222,14 +3222,14 @@ void pci_pm_init(struct pci_dev *dev)
> /* find PCI PM capability in list */
> pm = pci_find_capability(dev, PCI_CAP_ID_PM);
> if (!pm)
> - return;
> + goto poweron;
> /* Check device's ability to generate PME# */
> pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
>
> if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
> pci_err(dev, "unsupported PM cap regs version (%u)\n",
> pmc & PCI_PM_CAP_VER_MASK);
> - return;
> + goto poweron;
> }
>
> dev->pm_cap = pm;
> @@ -3274,6 +3274,7 @@ void pci_pm_init(struct pci_dev *dev)
> pci_read_config_word(dev, PCI_STATUS, &status);
> if (status & PCI_STATUS_IMM_READY)
> dev->imm_ready = 1;
> +poweron:
> pci_pm_power_up_and_verify_state(dev);
> pm_runtime_forbid(&dev->dev);
> pm_runtime_set_active(&dev->dev);
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM
2025-06-11 23:31 [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM Mario Limonciello
2025-06-12 0:40 ` Sathyanarayanan Kuppuswamy
@ 2025-06-12 7:01 ` Nicolas Dichtel
2025-06-12 9:39 ` Rafael J. Wysocki
2025-06-13 19:43 ` Bjorn Helgaas
3 siblings, 0 replies; 5+ messages in thread
From: Nicolas Dichtel @ 2025-06-12 7:01 UTC (permalink / raw)
To: Mario Limonciello, mario.limonciello, bhelgaas, rafael
Cc: Alex Williamson, Giovanni Cabiddu, linux-pci
Le 12/06/2025 à 01:31, Mario Limonciello a écrit :
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> commit 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when
> initializing") intended to put PCI devices into D0, but in doing so
> unintentionally changed runtime PM initialization not to occur on
> devices that don't support PCI PM. This caused a regression in vfio-pci
> due to an imbalance with it's use.
>
> Adjust the logic in pci_pm_init() so that even if PCI PM isn't supported
> runtime PM is still initialized.
>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m7e8929d6421690dc8bd6dc639d86c2b4db27cbc4
> Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m40d277dcdb9be64a1609a82412d1aa906263e201
> Tested-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Fixes: 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Thanks for the quick fix!
Regards,
Nicolas
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM
2025-06-11 23:31 [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM Mario Limonciello
2025-06-12 0:40 ` Sathyanarayanan Kuppuswamy
2025-06-12 7:01 ` Nicolas Dichtel
@ 2025-06-12 9:39 ` Rafael J. Wysocki
2025-06-13 19:43 ` Bjorn Helgaas
3 siblings, 0 replies; 5+ messages in thread
From: Rafael J. Wysocki @ 2025-06-12 9:39 UTC (permalink / raw)
To: Mario Limonciello
Cc: mario.limonciello, bhelgaas, rafael, Alex Williamson,
Giovanni Cabiddu, Nicolas Dichtel, linux-pci
On Thu, Jun 12, 2025 at 1:31 AM Mario Limonciello <superm1@kernel.org> wrote:
>
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> commit 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when
> initializing") intended to put PCI devices into D0, but in doing so
> unintentionally changed runtime PM initialization not to occur on
> devices that don't support PCI PM. This caused a regression in vfio-pci
> due to an imbalance with it's use.
>
> Adjust the logic in pci_pm_init() so that even if PCI PM isn't supported
> runtime PM is still initialized.
>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m7e8929d6421690dc8bd6dc639d86c2b4db27cbc4
> Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m40d277dcdb9be64a1609a82412d1aa906263e201
> Tested-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Fixes: 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
> ---
> v2:
> * remove pointless return
> ---
> drivers/pci/pci.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 3dd44d1ad829b..160a9a482c732 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3222,14 +3222,14 @@ void pci_pm_init(struct pci_dev *dev)
> /* find PCI PM capability in list */
> pm = pci_find_capability(dev, PCI_CAP_ID_PM);
> if (!pm)
> - return;
> + goto poweron;
> /* Check device's ability to generate PME# */
> pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
>
> if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
> pci_err(dev, "unsupported PM cap regs version (%u)\n",
> pmc & PCI_PM_CAP_VER_MASK);
> - return;
> + goto poweron;
> }
>
> dev->pm_cap = pm;
> @@ -3274,6 +3274,7 @@ void pci_pm_init(struct pci_dev *dev)
> pci_read_config_word(dev, PCI_STATUS, &status);
> if (status & PCI_STATUS_IMM_READY)
> dev->imm_ready = 1;
> +poweron:
> pci_pm_power_up_and_verify_state(dev);
> pm_runtime_forbid(&dev->dev);
> pm_runtime_set_active(&dev->dev);
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM
2025-06-11 23:31 [PATCH v2] PCI: Set up runtime PM on devices that don't support PCI PM Mario Limonciello
` (2 preceding siblings ...)
2025-06-12 9:39 ` Rafael J. Wysocki
@ 2025-06-13 19:43 ` Bjorn Helgaas
3 siblings, 0 replies; 5+ messages in thread
From: Bjorn Helgaas @ 2025-06-13 19:43 UTC (permalink / raw)
To: Mario Limonciello
Cc: mario.limonciello, bhelgaas, rafael, Alex Williamson,
Giovanni Cabiddu, Nicolas Dichtel, linux-pci
On Wed, Jun 11, 2025 at 06:31:16PM -0500, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> commit 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when
> initializing") intended to put PCI devices into D0, but in doing so
> unintentionally changed runtime PM initialization not to occur on
> devices that don't support PCI PM. This caused a regression in vfio-pci
> due to an imbalance with it's use.
>
> Adjust the logic in pci_pm_init() so that even if PCI PM isn't supported
> runtime PM is still initialized.
>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m7e8929d6421690dc8bd6dc639d86c2b4db27cbc4
> Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> Closes: https://lore.kernel.org/linux-pci/20250424043232.1848107-1-superm1@kernel.org/T/#m40d277dcdb9be64a1609a82412d1aa906263e201
> Tested-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Fixes: 4d4c10f763d7 ("PCI: Explicitly put devices into D0 when initializing")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
4d4c10f763d7 appeared in v6.16-rc1, so I applied this to pci/for-linus
for v6.16, thanks for the quick resolution!
> ---
> v2:
> * remove pointless return
> ---
> drivers/pci/pci.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 3dd44d1ad829b..160a9a482c732 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3222,14 +3222,14 @@ void pci_pm_init(struct pci_dev *dev)
> /* find PCI PM capability in list */
> pm = pci_find_capability(dev, PCI_CAP_ID_PM);
> if (!pm)
> - return;
> + goto poweron;
> /* Check device's ability to generate PME# */
> pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
>
> if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
> pci_err(dev, "unsupported PM cap regs version (%u)\n",
> pmc & PCI_PM_CAP_VER_MASK);
> - return;
> + goto poweron;
> }
>
> dev->pm_cap = pm;
> @@ -3274,6 +3274,7 @@ void pci_pm_init(struct pci_dev *dev)
> pci_read_config_word(dev, PCI_STATUS, &status);
> if (status & PCI_STATUS_IMM_READY)
> dev->imm_ready = 1;
> +poweron:
> pci_pm_power_up_and_verify_state(dev);
> pm_runtime_forbid(&dev->dev);
> pm_runtime_set_active(&dev->dev);
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread