| Message ID | 3006340.mglZY9ZPKY@vostro.rjw.lan (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Sat, 2013-02-09 at 15:29 +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > The ACPI scan lock has been introduced to prevent acpi_bus_scan() > and acpi_bus_trim() from running in parallel with each other for > overlapping ACPI namespace scopes. However, it is not sufficient > to do that, because if acpi_bus_scan() is run (for an overlapping > namespace scope) right after the acpi_bus_trim() in > acpi_bus_hot_remove_device(), the subsequent eject will remove > devices without removing the corresponding struct acpi_device > objects (and possibly companion "physical" device objects). > Therefore acpi_bus_hot_remove_device() has to acquire the scan > lock before carrying out the bus trimming and hold it through > the evaluation of _EJ0, so make that happen. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Looks good. Acked-by: Toshi Kani <toshi.kani@hp.com> Thanks, -Toshi > --- > drivers/acpi/scan.c | 31 +++++++++++++++++-------------- > 1 file changed, 17 insertions(+), 14 deletions(-) > > Index: test/drivers/acpi/scan.c > =================================================================== > --- test.orig/drivers/acpi/scan.c > +++ test/drivers/acpi/scan.c > @@ -95,6 +95,8 @@ acpi_device_modalias_show(struct device > } > static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL); > > +static void __acpi_bus_trim(struct acpi_device *start); > + > /** > * acpi_bus_hot_remove_device: hot-remove a device and its children > * @context: struct acpi_eject_event pointer (freed in this func) > @@ -114,10 +116,12 @@ void acpi_bus_hot_remove_device(void *co > acpi_status status = AE_OK; > u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ > > + mutex_lock(&acpi_scan_lock); > + > ACPI_DEBUG_PRINT((ACPI_DB_INFO, > "Hot-removing device %s...\n", dev_name(&device->dev))); > > - acpi_bus_trim(device); > + __acpi_bus_trim(device); > /* Device node has been released. */ > device = NULL; > > @@ -146,18 +150,14 @@ void acpi_bus_hot_remove_device(void *co > status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL); > if (ACPI_FAILURE(status)) { > if (status != AE_NOT_FOUND) > - printk(KERN_WARNING PREFIX > - "Eject device failed\n"); > - goto err_out; > - } > + acpi_handle_warn(handle, "Eject failed\n"); > > - kfree(context); > - return; > + /* Tell the firmware the hot-remove operation has failed. */ > + acpi_evaluate_hotplug_ost(handle, ej_event->event, > + ost_code, NULL); > + } > > -err_out: > - /* Inform firmware the hot-remove operation has completed w/ error */ > - (void) acpi_evaluate_hotplug_ost(handle, > - ej_event->event, ost_code, NULL); > + mutex_unlock(&acpi_scan_lock); > kfree(context); > return; > } > @@ -1686,10 +1686,8 @@ static acpi_status acpi_bus_remove(acpi_ > return AE_OK; > } > > -void acpi_bus_trim(struct acpi_device *start) > +static void __acpi_bus_trim(struct acpi_device *start) > { > - mutex_lock(&acpi_scan_lock); > - > /* > * Execute acpi_bus_device_detach() as a post-order callback to detach > * all ACPI drivers from the device nodes being removed. > @@ -1704,7 +1702,12 @@ void acpi_bus_trim(struct acpi_device *s > acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL, > acpi_bus_remove, NULL, NULL); > acpi_bus_remove(start->handle, 0, NULL, NULL); > +} > > +void acpi_bus_trim(struct acpi_device *start) > +{ > + mutex_lock(&acpi_scan_lock); > + __acpi_bus_trim(start); > mutex_unlock(&acpi_scan_lock); > } > EXPORT_SYMBOL_GPL(acpi_bus_trim); > -- 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
Index: test/drivers/acpi/scan.c =================================================================== --- test.orig/drivers/acpi/scan.c +++ test/drivers/acpi/scan.c @@ -95,6 +95,8 @@ acpi_device_modalias_show(struct device } static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL); +static void __acpi_bus_trim(struct acpi_device *start); + /** * acpi_bus_hot_remove_device: hot-remove a device and its children * @context: struct acpi_eject_event pointer (freed in this func) @@ -114,10 +116,12 @@ void acpi_bus_hot_remove_device(void *co acpi_status status = AE_OK; u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ + mutex_lock(&acpi_scan_lock); + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Hot-removing device %s...\n", dev_name(&device->dev))); - acpi_bus_trim(device); + __acpi_bus_trim(device); /* Device node has been released. */ device = NULL; @@ -146,18 +150,14 @@ void acpi_bus_hot_remove_device(void *co status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL); if (ACPI_FAILURE(status)) { if (status != AE_NOT_FOUND) - printk(KERN_WARNING PREFIX - "Eject device failed\n"); - goto err_out; - } + acpi_handle_warn(handle, "Eject failed\n"); - kfree(context); - return; + /* Tell the firmware the hot-remove operation has failed. */ + acpi_evaluate_hotplug_ost(handle, ej_event->event, + ost_code, NULL); + } -err_out: - /* Inform firmware the hot-remove operation has completed w/ error */ - (void) acpi_evaluate_hotplug_ost(handle, - ej_event->event, ost_code, NULL); + mutex_unlock(&acpi_scan_lock); kfree(context); return; } @@ -1686,10 +1686,8 @@ static acpi_status acpi_bus_remove(acpi_ return AE_OK; } -void acpi_bus_trim(struct acpi_device *start) +static void __acpi_bus_trim(struct acpi_device *start) { - mutex_lock(&acpi_scan_lock); - /* * Execute acpi_bus_device_detach() as a post-order callback to detach * all ACPI drivers from the device nodes being removed. @@ -1704,7 +1702,12 @@ void acpi_bus_trim(struct acpi_device *s acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL, acpi_bus_remove, NULL, NULL); acpi_bus_remove(start->handle, 0, NULL, NULL); +} +void acpi_bus_trim(struct acpi_device *start) +{ + mutex_lock(&acpi_scan_lock); + __acpi_bus_trim(start); mutex_unlock(&acpi_scan_lock); } EXPORT_SYMBOL_GPL(acpi_bus_trim);