ACPI / EC: Work around method reentrancy limit in ACPICA for _Qxx
A regression is caused by the following commit: Commit:02b771b64b
Subject: ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations In this commit, using system workqueue causes that the maximum parallel executions of _Qxx can exceed 255. This violates the method reentrancy limit in ACPICA and generates the following error log: ACPI Error: Method reached maximum reentrancy limit (255) (20150818/dsmethod-341) This patch creates a seperate workqueue and limits the number of parallel _Qxx evaluations down to a configurable value (can be tuned against number of online CPUs). Since EC events are handled after driver probe, we can create the workqueue in acpi_ec_init(). Fixes:02b771b64b
(ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations) Link: https://bugzilla.kernel.org/show_bug.cgi?id=135691 Cc: 4.3+ <stable@vger.kernel.org> # 4.3+ Reported-and-tested-by: Helen Buus <ubuntu@hbuus.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
parent
bc539567ab
commit
e1191bd4f6
|
@ -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;
|
||||
}
|
||||
|
@ -1649,15 +1655,41 @@ 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;
|
||||
}
|
||||
|
||||
|
@ -1667,5 +1699,6 @@ static void __exit acpi_ec_exit(void)
|
|||
{
|
||||
|
||||
acpi_bus_unregister_driver(&acpi_ec_driver);
|
||||
acpi_ec_query_exit();
|
||||
}
|
||||
#endif /* 0 */
|
||||
|
|
Loading…
Reference in a new issue