I'd hold down this patch if we are going to work on the new mechanism for ACPI device scan/hotplug... thanks, rui On Tue, 2008-02-26 at 16:04 +0800, Zhao Yakui wrote: > Subject: ACPI : Load device driver according to the status of acpi device > >From : Zhao Yakui <yakui.zhao@xxxxxxxxx> > > According to ACPI spec when the status of some device is not present > but functional, the device is valid and the children of this device > should be enumerated. It means that the device should be added to > linux acpi device tree. > But the device driver for this device should not be loaded. > > http://bugzilla.kernel.org/show_bug.cgi?id=3358 > > Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx> > Signed-off-by: Li Shaohua <shaohua.li@xxxxxxxxx> > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> > --- > drivers/acpi/bus.c | 16 ++++++++-------- > drivers/acpi/scan.c | 35 +++++++++++++++++++++++++---------- > drivers/pnp/pnpacpi/core.c | 6 +++++- > 3 files changed, 38 insertions(+), 19 deletions(-) > > Index: linux-2.6/drivers/acpi/bus.c > =================================================================== > --- linux-2.6.orig/drivers/acpi/bus.c > +++ linux-2.6/drivers/acpi/bus.c > @@ -94,21 +94,21 @@ int acpi_bus_get_status(struct acpi_devi > } > > /*child->status.present && > + child->status.functional > - * Otherwise we assume the status of our parent (unless we don't > - * have one, in which case status is implied). > + * According to ACPI spec some device can be present and functional > + * even if the parent is not present but functional. > + * In such conditions the child device should not inherit the status > + * from the parent. > */ > - else if (device->parent) > - device->status = device->parent->status; > else > STRUCT_TO_INT(device->status) = > ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | > ACPI_STA_DEVICE_UI | ACPI_STA_DEVICE_FUNCTIONING; > > if (device->status.functional && !device->status.present) { > - printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: " > - "functional but not present; setting present\n", > - device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status)); > - device->status.present = 1; > + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: " > + "functional but not present;\n", > + device->pnp.bus_id, > + (u32) STRUCT_TO_INT(device->status))); > } > > ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n", > Index: linux-2.6/drivers/acpi/scan.c > =================================================================== > --- linux-2.6.orig/drivers/acpi/scan.c > +++ linux-2.6/drivers/acpi/scan.c > @@ -258,6 +258,13 @@ int acpi_match_device_ids(struct acpi_de > { > const struct acpi_device_id *id; > > + /* > + * If the device is not present, it is unnecessary to load device > + * driver for it. > + */ > + if (!device->status.present) > + return -ENODEV; > + > if (device->flags.hardware_id) { > for (id = ids; id->id[0]; id++) { > if (!strcmp((char*)id->id, device->pnp.hardware_id)) > @@ -1195,15 +1202,18 @@ acpi_add_single_object(struct acpi_devic > result = -ENODEV; > goto end; > } > - if (!device->status.present) { > - /* Bay and dock should be handled even if absent */ > - if (!ACPI_SUCCESS( > - acpi_is_child_device(device, acpi_bay_match)) && > - !ACPI_SUCCESS( > - acpi_is_child_device(device, acpi_dock_match))) { > - result = -ENODEV; > - goto end; > - } > + /* > + * When the device is neither present nor functional, the > + * device should not be added to Linux ACPI device tree. > + * When the status of the device is not present but functinal, > + * it should be added to Linux ACPI tree. For example : bay > + * device , dock device. > + * In such conditions it is unncessary to check whether it is > + * bay device or dock device. > + */ > + if (!device->status.present && !device->status.functional) { > + result = -ENODEV; > + goto end; > } > break; > default: > @@ -1376,7 +1386,12 @@ static int acpi_bus_scan(struct acpi_dev > * TBD: Need notifications and other detection mechanisms > * in place before we can fully implement this. > */child->status.present && > + child->status.functional > - if (child->status.present) { > + /* > + * When the device is not present but functional, it is also > + * necessary to scan the children of this device. > + */ > + if (child->status.present || (!child->status.present && > + child->status.functional)) { > status = acpi_get_next_object(ACPI_TYPE_ANY, chandle, > NULL, NULL); > if (ACPI_SUCCESS(status)) { > Index: linux-2.6/drivers/pnp/pnpacpi/core.c > =================================================================== > --- linux-2.6.orig/drivers/pnp/pnpacpi/core.c > +++ linux-2.6/drivers/pnp/pnpacpi/core.c > @@ -166,9 +166,13 @@ static int __init pnpacpi_add_device(str > struct pnp_id *dev_id; > struct pnp_dev *dev; > > + /* > + * If a PnPacpi device is not present , the device > + * driver should not be loaded. > + */ > status = acpi_get_handle(device->handle, "_CRS", &temp); > if (ACPI_FAILURE(status) || !ispnpidacpi(acpi_device_hid(device)) || > - is_exclusive_device(device)) > + is_exclusive_device(device) || (!device->status.present)) > return 0; > > dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL); > > > - > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
