From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Revert
commit 50c0f43ff1199bbea5f0418d40df32f4d4029b13
Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Date: Thu Sep 4 15:13:29 2008 +0200
ACPI: EC: do transaction from interrupt context
From: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
It is easier and faster to do transaction directly from interrupt context
rather than waking control thread.
Also, cleaner GPE storm avoidance is implemented.
AK: Merged with earlier io port patch
Signed-off-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
due to a regression reported by Bart.
Cc: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
Cc: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/ec.c | 246 ++++++++++++++++++++++++--------------------
1 file changed, 135 insertions(+), 111 deletions(-)
diff -puN drivers/acpi/ec.c~revert-acpi-ec-do-transaction-from-interrupt-context drivers/acpi/ec.c
--- a/drivers/acpi/ec.c~revert-acpi-ec-do-transaction-from-interrupt-context
+++ a/drivers/acpi/ec.c
@@ -1,7 +1,7 @@
/*
- * ec.c - ACPI Embedded Controller Driver (v2.1)
+ * ec.c - ACPI Embedded Controller Driver (v2.0)
*
- * Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@xxxxxxx>
+ * Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@xxxxxxxxx>
* Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@xxxxxxxxx>
* Copyright (C) 2004 Luming Yu <luming.yu@xxxxxxxxx>
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@xxxxxxxxx>
@@ -26,7 +26,7 @@
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
-/* Uncomment next line to get verbose printout */
+/* Uncomment next line to get verbose print outs*/
/* #define DEBUG */
#include <linux/kernel.h>
@@ -65,18 +65,22 @@ enum ec_command {
ACPI_EC_COMMAND_QUERY = 0x84,
};
+/* EC events */
+enum ec_event {
+ ACPI_EC_EVENT_OBF_1 = 1, /* Output buffer full */
+ ACPI_EC_EVENT_IBF_0, /* Input buffer empty */
+};
+
#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
#define ACPI_EC_UDELAY 100 /* Wait 100us before polling EC again */
-#define ACPI_EC_STORM_THRESHOLD 20 /* number of false interrupts
- per one transaction */
-
enum {
+ EC_FLAGS_WAIT_GPE = 0, /* Don't check status until GPE arrives */
EC_FLAGS_QUERY_PENDING, /* Query is pending */
EC_FLAGS_GPE_MODE, /* Expect GPE to be sent for status change */
EC_FLAGS_NO_GPE, /* Don't use GPE mode */
- EC_FLAGS_GPE_STORM /* GPE storm detected */
+ EC_FLAGS_RESCHEDULE_POLL /* Re-schedule poll */
};
/* If we find an EC via the ECDT, we need to keep a ptr to its context */
@@ -91,14 +95,6 @@ struct acpi_ec_query_handler {
u8 query_bit;
};
-struct transaction_data {
- const u8 *wdata;
- u8 *rdata;
- u8 command;
- u8 wlen;
- u8 rlen;
-};
-
static struct acpi_ec {
acpi_handle handle;
unsigned long gpe;
@@ -109,7 +105,7 @@ static struct acpi_ec {
struct mutex lock;
wait_queue_head_t wait;
struct list_head list;
- struct transaction_data t;
+ struct delayed_work work;
atomic_t irq_count;
u8 handlers_installed;
} *boot_ec, *first_ec;
@@ -169,60 +165,69 @@ static inline void acpi_ec_write_data(st
outb(data, ec->data_addr);
}
-static int ec_transaction_done(struct acpi_ec *ec) {
- if (!ec->t.command)
- return 1;
- if (!ec->t.wlen && !ec->t.rlen)
- return 1;
+static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
+{
+ if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
+ return 0;
+ if (event == ACPI_EC_EVENT_OBF_1) {
+ if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
+ return 1;
+ } else if (event == ACPI_EC_EVENT_IBF_0) {
+ if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
+ return 1;
+ }
+
return 0;
}
-static void gpe_transaction(struct acpi_ec *ec, u8 status)
+static void ec_schedule_ec_poll(struct acpi_ec *ec)
{
- if (!ec->t.command)
- return;
- if (ec->t.wlen > 0) {
- if ((status & ACPI_EC_FLAG_IBF) == 0) {
- acpi_ec_write_data(ec, *(ec->t.wdata++));
- --ec->t.wlen;
- } else
- /* false interrupt, state didn't change */
- atomic_inc(&ec->irq_count);
-
- } else if (ec->t.rlen > 0) {
- if ((status & ACPI_EC_FLAG_OBF) == 1) {
- *(ec->t.rdata++) = acpi_ec_read_data(ec);
- --ec->t.rlen;
- } else
- /* false interrupt, state didn't change */
- atomic_inc(&ec->irq_count);
- }
+ if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
+ schedule_delayed_work(&ec->work,
+ msecs_to_jiffies(ACPI_EC_DELAY));
}
-static int acpi_ec_wait(struct acpi_ec *ec)
+static void ec_switch_to_poll_mode(struct acpi_ec *ec)
{
- if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
- msecs_to_jiffies(ACPI_EC_DELAY)))
- return 0;
- /* missing GPEs, switch back to poll mode */
- if (printk_ratelimit())
- pr_info(PREFIX "missing confirmations, "
- "switch off interrupt mode.\n");
set_bit(EC_FLAGS_NO_GPE, &ec->flags);
clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
- return 1;
+ acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
+ set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
}
-static void acpi_ec_gpe_query(void *ec_cxt);
-
-static int ec_check_sci(struct acpi_ec *ec, u8 state)
+static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
{
- if (state & ACPI_EC_FLAG_SCI) {
- if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
- return acpi_os_execute(OSL_EC_BURST_HANDLER,
- acpi_ec_gpe_query, ec);
+ atomic_set(&ec->irq_count, 0);
+ if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
+ likely(!force_poll)) {
+ if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
+ msecs_to_jiffies(ACPI_EC_DELAY)))
+ return 0;
+ clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+ if (acpi_ec_check_status(ec, event)) {
+ /* missing GPEs, switch back to poll mode */
+ if (printk_ratelimit())
+ pr_info(PREFIX "missing confirmations, "
+ "switch off interrupt mode.\n");
+ ec_switch_to_poll_mode(ec);
+ ec_schedule_ec_poll(ec);
+ return 0;
+ }
+ } else {
+ unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
+ clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+ while (time_before(jiffies, delay)) {
+ if (acpi_ec_check_status(ec, event))
+ return 0;
+ msleep(1);
+ }
+ if (acpi_ec_check_status(ec,event))
+ return 0;
}
- return 0;
+ pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
+ acpi_ec_read_status(ec),
+ (event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
+ return -ETIME;
}
static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
@@ -230,53 +235,45 @@ static int acpi_ec_transaction_unlocked(
u8 * rdata, unsigned rdata_len,
int force_poll)
{
- unsigned long delay;
+ int result = 0;
+ set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
pr_debug(PREFIX "transaction start\n");
- /* disable GPE during transaction if storm is detected */
- if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
- set_bit(EC_FLAGS_NO_GPE, &ec->flags);
- clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
- acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
- }
- atomic_set(&ec->irq_count, 0);
- /* fill in transaction structure */
- ec->t.wdata = wdata;
- ec->t.wlen = wdata_len;
- ec->t.rdata = rdata;
- ec->t.rlen = rdata_len;
- /* start transaction */
acpi_ec_write_cmd(ec, command);
- /* if we selected poll mode or failed in GPE-mode do a poll loop */
- if (force_poll ||
- !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
- acpi_ec_wait(ec)) {
- delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
- while (time_before(jiffies, delay)) {
- gpe_transaction(ec, acpi_ec_read_status(ec));
- msleep(1);
- if (ec_transaction_done(ec))
- goto end;
+ for (; wdata_len > 0; --wdata_len) {
+ result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
+ if (result) {
+ pr_err(PREFIX
+ "write_cmd timeout, command = %d\n", command);
+ goto end;
}
+ set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+ acpi_ec_write_data(ec, *(wdata++));
}
-end:
- pr_debug(PREFIX "transaction end\n");
- ec->t.command = 0;
- if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
- /* check if we received SCI during transaction */
- ec_check_sci(ec, acpi_ec_read_status(ec));
- /* it is safe to enable GPE outside of transaction */
- acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
- } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
- atomic_read(&ec->irq_count) > ACPI_EC_STORM_THRESHOLD)
- pr_debug(PREFIX "GPE storm detected\n");
- set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
- return 0;
-}
-static int ec_check_ibf0(struct acpi_ec *ec)
-{
- u8 status = acpi_ec_read_status(ec);
- return (status & ACPI_EC_FLAG_IBF) == 0;
+ if (!rdata_len) {
+ result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
+ if (result) {
+ pr_err(PREFIX
+ "finish-write timeout, command = %d\n", command);
+ goto end;
+ }
+ } else if (command == ACPI_EC_COMMAND_QUERY)
+ clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
+
+ for (; rdata_len > 0; --rdata_len) {
+ result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
+ if (result) {
+ pr_err(PREFIX "read timeout, command = %d\n", command);
+ goto end;
+ }
+ /* Don't expect GPE after last read */
+ if (rdata_len > 1)
+ set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+ *(rdata++) = acpi_ec_read_data(ec);
+ }
+ end:
+ pr_debug(PREFIX "transaction end\n");
+ return result;
}
static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
@@ -302,8 +299,8 @@ static int acpi_ec_transaction(struct ac
}
}
- if (!wait_event_timeout(ec->wait, ec_check_ibf0(ec),
- msecs_to_jiffies(ACPI_EC_DELAY))) {
+ status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
+ if (status) {
pr_err(PREFIX "input buffer is not empty, "
"aborting transaction\n");
goto end;
@@ -440,7 +437,6 @@ static int acpi_ec_query(struct acpi_ec
*/
result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
- clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
if (result)
return result;
@@ -519,17 +515,24 @@ static u32 acpi_ec_gpe_handler(void *dat
{
acpi_status status = AE_OK;
struct acpi_ec *ec = data;
- u8 state;
+ u8 state = acpi_ec_read_status(ec);
pr_debug(PREFIX "~~~> interrupt\n");
- state = acpi_ec_read_status(ec);
-
- gpe_transaction(ec, state);
- if ((status & ACPI_EC_FLAG_IBF) == 0)
+ atomic_inc(&ec->irq_count);
+ if (atomic_read(&ec->irq_count) > 5) {
+ pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
+ ec_switch_to_poll_mode(ec);
+ goto end;
+ }
+ clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+ if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
wake_up(&ec->wait);
- status = ec_check_sci(ec, state);
- if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
+ if (state & ACPI_EC_FLAG_SCI) {
+ if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
+ status = acpi_os_execute(OSL_EC_BURST_HANDLER,
+ acpi_ec_gpe_query, ec);
+ } else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
!test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
in_interrupt()) {
/* this is non-query, must be confirmation */
@@ -537,11 +540,21 @@ static u32 acpi_ec_gpe_handler(void *dat
pr_info(PREFIX "non-query interrupt received,"
" switching to interrupt mode\n");
set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+ clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
}
+end:
+ ec_schedule_ec_poll(ec);
return ACPI_SUCCESS(status) ?
ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
}
+static void do_ec_poll(struct work_struct *work)
+{
+ struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
+ atomic_set(&ec->irq_count, 0);
+ (void)acpi_ec_gpe_handler(ec);
+}
+
/* --------------------------------------------------------------------------
Address Space Management
-------------------------------------------------------------------------- */
@@ -683,6 +696,7 @@ static struct acpi_ec *make_acpi_ec(void
mutex_init(&ec->lock);
init_waitqueue_head(&ec->wait);
INIT_LIST_HEAD(&ec->list);
+ INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
atomic_set(&ec->irq_count, 0);
return ec;
}
@@ -722,8 +736,15 @@ ec_parse_device(acpi_handle handle, u32
return AE_CTRL_TERMINATE;
}
+static void ec_poll_stop(struct acpi_ec *ec)
+{
+ clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
+ cancel_delayed_work(&ec->work);
+}
+
static void ec_remove_handlers(struct acpi_ec *ec)
{
+ ec_poll_stop(ec);
if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
pr_err(PREFIX "failed to remove space handler\n");
@@ -828,12 +849,14 @@ static int ec_install_handlers(struct ac
if (ec->handlers_installed)
return 0;
status = acpi_install_gpe_handler(NULL, ec->gpe,
- ACPI_GPE_EDGE_TRIGGERED,
- &acpi_ec_gpe_handler, ec);
+ ACPI_GPE_EDGE_TRIGGERED,
+ &acpi_ec_gpe_handler, ec);
if (ACPI_FAILURE(status))
return -ENODEV;
+
acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
+
status = acpi_install_address_space_handler(ec->handle,
ACPI_ADR_SPACE_EC,
&acpi_ec_space_handler,
@@ -864,6 +887,7 @@ static int acpi_ec_start(struct acpi_dev
/* EC is fully operational, allow queries */
clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
+ ec_schedule_ec_poll(ec);
return ret;
}
_
--
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
