Re: [PATCH] PCI / ACPI: Make acpiphp ignore root bridges using PCIe native hotplug

Kenji Kaneshige
2011-10-25T13:10:35Z

Looks good.
This is also needed for SHPC native hotplug.

Regards,
Kenji Kaneshige

(2011/10/22 7:43), Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki<rjw@sisk.pl>
>
> If the kernel has requested control of the PCIe native hotplug
> feature for a given root complex, the acpiphp driver should not try
> to handle that root complex and it should leave it to pciehp.
> Failing to do so causes problems to happen if acpiphp is loaded
> before pciehp on such systems.
>
> To address this issue make find_root_bridges() ignore PCIe root
> complexes with PCIe native hotplug enabled and make add_bridge()
> return error code if PCIe native hotplug is enabled for the given
> root port. This causes acpiphp to refuse to load if PCIe native
> hotplug is enabled for all complexes and to refuse binding to
> the root complexes with PCIe native hotplug is enabled.
>
> Signed-off-by: Rafael J. Wysocki<rjw@sisk.pl>
> ---
> drivers/pci/hotplug/acpiphp_glue.c | 29 ++++++++++++++++++++++++-----
> 1 file changed, 24 insertions(+), 5 deletions(-)
>
> Index: linux/drivers/pci/hotplug/acpiphp_glue.c
> ===================================================================
> --- linux.orig/drivers/pci/hotplug/acpiphp_glue.c
> +++ linux/drivers/pci/hotplug/acpiphp_glue.c
> @@ -458,8 +458,17 @@ static int add_bridge(acpi_handle handle
> {
> acpi_status status;
> unsigned long long tmp;
> + struct acpi_pci_root *root;
> acpi_handle dummy_handle;
>
> + /*
> + * We shouldn't use this bridge if PCIe native hotplug control has been
> + * granted by the BIOS for it.
> + */
> + root = acpi_pci_find_root(handle);
> + if (root&& (root->osc_control_set& OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
> + return -ENODEV;
> +
> /* if the bridge doesn't have _STA, we assume it is always there */
> status = acpi_get_handle(handle, "_STA",&dummy_handle);
> if (ACPI_SUCCESS(status)) {
> @@ -1297,13 +1306,23 @@ static void handle_hotplug_event_func(ac
> static acpi_status
> find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
> {
> + struct acpi_pci_root *root;
> int *count = (int *)context;
>
> - if (acpi_is_root_bridge(handle)) {
> - acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> - handle_hotplug_event_bridge, NULL);
> - (*count)++;
> - }
> + if (!acpi_is_root_bridge(handle))
> + return AE_OK;
> +
> + root = acpi_pci_find_root(handle);
> + if (!root)
> + return AE_OK;
> +
> + if (root->osc_control_set& OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)
> + return AE_OK;
> +
> + (*count)++;
> + acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> + handle_hotplug_event_bridge, NULL);
> +
> return AE_OK ;
> }
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>