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Fix startup race initialising ACPI CM battery structures on MacBookPro.

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During acpi_cmbat_attach() the acpi_cmbat_init_battery() notification
handler is registered. It has been observed this notification handler
can be called instantly, before the attach routine has returned. In
the notification handler there is a call to device_is_attached() which
returns false. Because the softc is set we know an attach is in
progress and the fix is simply to wait and try again in this case.

Reviewed by:		avg @
MFC after:		1 week
This commit is contained in:
Hans Petter Selasky 2017-02-27 08:36:51 +00:00
parent 3f072d6948
commit a26871e7ff
1 changed files with 29 additions and 5 deletions
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34
sys/dev/acpica/acpi_cmbat.c
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@ -164,6 +164,16 @@ acpi_cmbat_detach(device_t dev)
handle = acpi_get_handle(dev);
AcpiRemoveNotifyHandler(handle, ACPI_ALL_NOTIFY, acpi_cmbat_notify_handler);
acpi_battery_remove(dev);
/*
* Force any pending notification handler calls to complete by
* requesting cmbat serialisation while freeing and clearing the
* softc pointer:
*/
ACPI_SERIAL_BEGIN(cmbat);
device_set_softc(dev, NULL);
ACPI_SERIAL_END(cmbat);
return (0);
}
@ -436,7 +446,6 @@ acpi_cmbat_init_battery(void *arg)
device_t dev;
dev = (device_t)arg;
sc = device_get_softc(dev);
ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev),
"battery initialization start\n");
@ -446,18 +455,33 @@ acpi_cmbat_init_battery(void *arg)
* to wait a while.
*/
for (retry = 0; retry < ACPI_CMBAT_RETRY_MAX; retry++, AcpiOsSleep(10000)) {
/* batteries on DOCK can be ejected w/ DOCK during retrying */
if (!device_is_attached(dev))
/*
* Batteries on DOCK can be ejected w/ DOCK during retrying.
*
* If there is a valid softc pointer the device may be in
* attaching, attached or detaching state. If the state is
* different from attached retry getting the device state
* until it becomes stable. This solves a race if the ACPI
* notification handler is called during attach, because
* device_is_attached() doesn't return non-zero until after
* the attach code has been executed.
*/
ACPI_SERIAL_BEGIN(cmbat);
sc = device_get_softc(dev);
if (sc == NULL) {
ACPI_SERIAL_END(cmbat);
return;
}
if (!acpi_BatteryIsPresent(dev))
if (!acpi_BatteryIsPresent(dev) || !device_is_attached(dev)) {
ACPI_SERIAL_END(cmbat);
continue;
}
/*
* Only query the battery if this is the first try or the specific
* type of info is still invalid.
*/
ACPI_SERIAL_BEGIN(cmbat);
if (retry == 0 || !acpi_battery_bst_valid(&sc->bst)) {
timespecclear(&sc->bst_lastupdated);
acpi_cmbat_get_bst(dev);