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authorLinus Torvalds <torvalds@linux-foundation.org>2016-08-05 23:29:05 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-05 23:29:05 -0400
commit0524b422fa39fe3dd9454c8667da283241dde9e7 (patch)
tree9015be75884a68215e50809dcbc4ed9c838c662d
parent11d8ec408d0aa2dae7ca89f95e497b8f22427b20 (diff)
parent4dc14b343d47426858f3fb1c8669059b7e3f98d4 (diff)
downloadlinux-0524b422fa39fe3dd9454c8667da283241dde9e7.tar.bz2
Merge tag 'acpi-extra-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI updates from Rafael Wysocki: "Two more fixes in ACPI drivers, one in the ACPI EC driver (stable-candidate) and one in the ACPI button driver. Specifics: - An ACPI EC driver fix from the 4.3 cycle may cause the ACPICA's method reentrancy limit to be exceeded for a _Qxx method due to a large number of concurrent EC operations, so prevent that from happening by moving the EC handling into a separate workqueue with a limit on the number of concurrently executed work items (Lv Zheng) - Fix the cleanup code in the ACPI button driver that forgets to clear two variables on exit which causes an error to occur on the next attmpt to load the driver (Benjamin Tissoires)" * tag 'acpi-extra-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / EC: Work around method reentrancy limit in ACPICA for _Qxx ACPI / button: remove pointer to old lid_sysfs on unbind
-rw-r--r--drivers/acpi/button.c4
-rw-r--r--drivers/acpi/ec.c41
2 files changed, 41 insertions, 4 deletions
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 148f4e5ca104..31abb0bdd4f2 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -232,8 +232,10 @@ remove_dev_dir:
acpi_device_dir(device) = NULL;
remove_lid_dir:
remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
+ acpi_lid_dir = NULL;
remove_button_dir:
remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
+ acpi_button_dir = NULL;
goto done;
}
@@ -250,7 +252,9 @@ static int acpi_button_remove_fs(struct acpi_device *device)
acpi_lid_dir);
acpi_device_dir(device) = NULL;
remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
+ acpi_lid_dir = NULL;
remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
+ acpi_button_dir = NULL;
return 0;
}
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 999a10914678..e7bd57cc550a 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -101,6 +101,7 @@ enum ec_command {
#define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
* when trying to clear the EC */
+#define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
enum {
EC_FLAGS_QUERY_PENDING, /* Query is pending */
@@ -121,6 +122,10 @@ static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
module_param(ec_delay, uint, 0644);
MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
+static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
+module_param(ec_max_queries, uint, 0644);
+MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
+
static bool ec_busy_polling __read_mostly;
module_param(ec_busy_polling, bool, 0644);
MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
@@ -174,6 +179,7 @@ static void acpi_ec_event_processor(struct work_struct *work);
struct acpi_ec *boot_ec, *first_ec;
EXPORT_SYMBOL(first_ec);
+static struct workqueue_struct *ec_query_wq;
static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
@@ -1098,7 +1104,7 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
* work queue execution.
*/
ec_dbg_evt("Query(0x%02x) scheduled", value);
- if (!schedule_work(&q->work)) {
+ if (!queue_work(ec_query_wq, &q->work)) {
ec_dbg_evt("Query(0x%02x) overlapped", value);
result = -EBUSY;
}
@@ -1660,15 +1666,41 @@ static struct acpi_driver acpi_ec_driver = {
},
};
+static inline int acpi_ec_query_init(void)
+{
+ if (!ec_query_wq) {
+ ec_query_wq = alloc_workqueue("kec_query", 0,
+ ec_max_queries);
+ if (!ec_query_wq)
+ return -ENODEV;
+ }
+ return 0;
+}
+
+static inline void acpi_ec_query_exit(void)
+{
+ if (ec_query_wq) {
+ destroy_workqueue(ec_query_wq);
+ ec_query_wq = NULL;
+ }
+}
+
int __init acpi_ec_init(void)
{
- int result = 0;
+ int result;
+ /* register workqueue for _Qxx evaluations */
+ result = acpi_ec_query_init();
+ if (result)
+ goto err_exit;
/* Now register the driver for the EC */
result = acpi_bus_register_driver(&acpi_ec_driver);
- if (result < 0)
- return -ENODEV;
+ if (result)
+ goto err_exit;
+err_exit:
+ if (result)
+ acpi_ec_query_exit();
return result;
}
@@ -1678,5 +1710,6 @@ static void __exit acpi_ec_exit(void)
{
acpi_bus_unregister_driver(&acpi_ec_driver);
+ acpi_ec_query_exit();
}
#endif /* 0 */