On Friday 14 August 2009 12:18:47 pm Hugh Dickins wrote:
> On Fri, 14 Aug 2009, Bjorn Helgaas wrote:
> > I don't quite understand how this oops happens, though. It seems that
> > we crashed in this path:
> >
> > acpi_device_probe
> > acpi_bus_driver_init
> > driver->ops.add (calls acpi_video_bus_add)
> > acpi_device_install_notify_handler
> > hid = acpi_device_hid(device)
> > strcmp(hid, ACPI_BUTTON_HID_POWERF))
> > *** OOPS, hid == NULL ***
> >
> > But the acpi_video_bus driver claims devices using ACPI_VIDEO_HID
> > ("LNXVIDEO"), and acpi_device_set_id() already does synthesize
> > that HID, so acpi_device_hid() should have been valid. So why
> > did we oops?
>
> The backtrace I jotted down, from Intel 915 graphics, looked like this
> (acpi_device_install_notify_handler is inlined into acpi_device_probe):
>
> strcmp
> acpi_device_probe
> really_probe
> driver_probe_device
> __driver_attach
> bus_for_each_dev
> driver_attach
> bus_add_driver
> driver_register
> acpi_bus_register
> acpi_video_register
> intel_opregion_init
> i915_driver_load
> drm_get_dev
> drm_init
> i915_init
> do_one_initcall
> do_basic_setup
> kernel_init
> kernel_thread_helper
Likely the same issue as Valdis saw, but I don't see the actual
problem yet. If it's convenient, the patch below might shed a
little light.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 781435d..e8de598 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -376,6 +376,12 @@ static int acpi_device_install_notify_handler(struct acpi_device *device)
char *hid;
hid = acpi_device_hid(device);
+ if (!hid || strlen(hid) == 0) {
+ printk(KERN_INFO PREFIX
+ "install notify handler for %s, no HID!\n",
+ dev_name(&device->dev));
+ hid = "";
+ }
if (!strcmp(hid, ACPI_BUTTON_HID_POWERF))
status =
acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
@@ -420,6 +426,8 @@ static int acpi_device_probe(struct device * dev)
ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
if (!ret) {
+ printk(KERN_INFO PREFIX "binding driver [%s] to device [%s]\n",
+ acpi_drv->name, acpi_dev->pnp.bus_id);
if (acpi_dev->bus_ops.acpi_op_start)
acpi_start_single_object(acpi_dev);
@@ -1182,6 +1190,7 @@ acpi_add_single_object(struct acpi_device **child,
{
int result = 0;
struct acpi_device *device = NULL;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
if (!child)
@@ -1315,9 +1324,14 @@ acpi_add_single_object(struct acpi_device **child,
}
end:
- if (!result)
+ if (!result) {
+ acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+ printk(KERN_INFO PREFIX "adding %s [%s] HID %s\n",
+ dev_name(&device->dev), (char *) buffer.pointer,
+ acpi_device_hid(device) ? acpi_device_hid(device) :
+ "(null)");
*child = device;
- else {
+ } else {
kfree(device->pnp.cid_list);
kfree(device);
}
--
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
