Re: [bug report] nvme not re-recognize when changed M.2 SSD in S3 mode

Lukas Wunner
2024-04-10T14:58:36Z

On Wed, Apr 10, 2024 at 12:07:40PM +0200, Lukas Wunner wrote:
> --- a/drivers/pci/hotplug/pciehp_core.c
> +++ b/drivers/pci/hotplug/pciehp_core.c
> @@ -152,6 +152,25 @@ static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
> return 0;
> }
>
> +static bool pciehp_device_replaced(struct controller *ctrl)
> +{
> + struct pci_dev *pdev;

I've realized this needs to be

+ struct pci_dev *pdev __free(pci_dev_put);

to avoid leaking a ref on the child device. For testing purposes,
the patch should still be fine without this change, but I'll have to
fix this up if/when submitting a proper patch.

> + u32 reg;
> +
> + pdev = pci_get_slot(ctrl->pcie->port->subordinate, PCI_DEVFN(0, 0));
> + if (!pdev)
> + return true;
> +
> + if (!pci_bus_read_dev_vendor_id(ctrl->pcie->port->subordinate,
> + PCI_DEVFN(0, 0), &reg, 0))
> + return true;
> +
> + if (reg != (pdev->vendor | (pdev->device << 16)))
> + return true;
> +
> + return false;
> +}
> +
> /**
> * pciehp_check_presence() - synthesize event if presence has changed
> * @ctrl: controller to check
> @@ -172,7 +191,8 @@ static void pciehp_check_presence(struct controller *ctrl)
>
> occupied = pciehp_card_present_or_link_active(ctrl);
> if ((occupied > 0 && (ctrl->state == OFF_STATE ||
> - ctrl->state == BLINKINGON_STATE)) ||
> + ctrl->state == BLINKINGON_STATE ||
> + pciehp_device_replaced(ctrl))) ||
> (!occupied && (ctrl->state == ON_STATE ||
> ctrl->state == BLINKINGOFF_STATE)))
> pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);