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acpi_ec: changes in communication with hardware

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Short description of the changes:
- attempt to retry some commands for which it is possible (read, query)
- always make a short sleep before checking EC status in polled mode
- periodically poll EC status in interrupt mode
- change logic for detecting broken interrupt delivery and falling back
  to polled mode
- check that EC is ready for input before starting a new command, wait
  if necessary

This commit is based on the original patch by David Naylor.

PR:		kern/150517
Submitted by:	David Naylor <naylor.b.david@gmail.com>
Reviewed by:	jkim
MFC after:	3 weeks
This commit is contained in:
avg 2010-10-12 17:53:01 +00:00
parent 55173efe7f
commit 25fc6050f9
1 changed files with 89 additions and 83 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

172
sys/dev/acpica/acpi_ec.c
View File

@ -153,7 +153,7 @@ struct acpi_ec_softc {
int ec_glkhandle;
int ec_burstactive;
int ec_sci_pend;
u_int ec_gencount;
volatile u_int ec_gencount;
int ec_suspending;
};
@ -165,7 +165,7 @@ struct acpi_ec_softc {
#define EC_LOCK_TIMEOUT 1000
/* Default delay in microseconds between each run of the status polling loop. */
#define EC_POLL_DELAY 5
#define EC_POLL_DELAY 50
/* Total time in ms spent waiting for a response from EC. */
#define EC_TIMEOUT 750
@ -599,12 +599,32 @@ acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
return (0);
}
static ACPI_STATUS
EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
{
ACPI_STATUS status;
EC_STATUS ec_status;
status = AE_NO_HARDWARE_RESPONSE;
ec_status = EC_GET_CSR(sc);
if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
sc->ec_burstactive = FALSE;
}
if (EVENT_READY(event, ec_status)) {
CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
status = AE_OK;
}
return (status);
}
static void
EcGpeQueryHandler(void *Context)
{
struct acpi_ec_softc *sc = (struct acpi_ec_softc *)Context;
UINT8 Data;
ACPI_STATUS Status;
int retry;
char qxx[5];
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
@ -625,7 +645,16 @@ EcGpeQueryHandler(void *Context)
* that may arise from running the query from causing another query
* to be queued, we clear the pending flag only after running it.
*/
Status = EcCommand(sc, EC_COMMAND_QUERY);
for (retry = 0; retry < 2; retry++) {
Status = EcCommand(sc, EC_COMMAND_QUERY);
if (ACPI_SUCCESS(Status))
break;
if (EcCheckStatus(sc, "retr_check",
EC_EVENT_INPUT_BUFFER_EMPTY) == AE_OK)
continue;
else
break;
}
sc->ec_sci_pend = FALSE;
if (ACPI_FAILURE(Status)) {
EcUnlock(sc);
@ -678,7 +707,7 @@ EcGpeHandler(void *Context)
* address and then data values.)
*/
atomic_add_int(&sc->ec_gencount, 1);
wakeup(&sc->ec_gencount);
wakeup(&sc);
/*
* If the EC_SCI bit of the status register is set, queue a query handler.
@ -788,69 +817,28 @@ EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 Width,
return_ACPI_STATUS (Status);
}
static ACPI_STATUS
EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
{
ACPI_STATUS status;
EC_STATUS ec_status;
status = AE_NO_HARDWARE_RESPONSE;
ec_status = EC_GET_CSR(sc);
if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
sc->ec_burstactive = FALSE;
}
if (EVENT_READY(event, ec_status)) {
CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
status = AE_OK;
}
return (status);
}
static ACPI_STATUS
EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
{
static int no_intr = 0;
ACPI_STATUS Status;
int count, i, slp_ival;
int count, i, need_poll, slp_ival;
ACPI_SERIAL_ASSERT(ec);
Status = AE_NO_HARDWARE_RESPONSE;
int need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
/*
* The main CPU should be much faster than the EC. So the status should
* be "not ready" when we start waiting. But if the main CPU is really
* slow, it's possible we see the current "ready" response. Since that
* can't be distinguished from the previous response in polled mode,
* this is a potential issue. We really should have interrupts enabled
* during boot so there is no ambiguity in polled mode.
*
* If this occurs, we add an additional delay before actually entering
* the status checking loop, hopefully to allow the EC to go to work
* and produce a non-stale status.
*/
if (need_poll) {
static int once;
if (EcCheckStatus(sc, "pre-check", Event) == AE_OK) {
if (!once) {
device_printf(sc->ec_dev,
"warning: EC done before starting event wait\n");
once = 1;
}
AcpiOsStall(10);
}
}
need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
/* Wait for event by polling or GPE (interrupt). */
if (need_poll) {
count = (ec_timeout * 1000) / EC_POLL_DELAY;
if (count == 0)
count = 1;
DELAY(10);
for (i = 0; i < count; i++) {
Status = EcCheckStatus(sc, "poll", Event);
if (Status == AE_OK)
break;
AcpiOsStall(EC_POLL_DELAY);
DELAY(EC_POLL_DELAY);
}
} else {
slp_ival = hz / 1000;
@ -869,34 +857,37 @@ EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
* EC query).
*/
for (i = 0; i < count; i++) {
if (gen_count != sc->ec_gencount) {
/*
* Record new generation count. It's possible the GPE was
* just to notify us that a query is needed and we need to
* wait for a second GPE to signal the completion of the
* event we are actually waiting for.
*/
gen_count = sc->ec_gencount;
Status = EcCheckStatus(sc, "sleep", Event);
if (Status == AE_OK)
break;
if (gen_count == sc->ec_gencount)
tsleep(&sc, 0, "ecgpe", slp_ival);
/*
* Record new generation count. It's possible the GPE was
* just to notify us that a query is needed and we need to
* wait for a second GPE to signal the completion of the
* event we are actually waiting for.
*/
Status = EcCheckStatus(sc, "sleep", Event);
if (Status == AE_OK) {
if (gen_count == sc->ec_gencount)
no_intr++;
else
no_intr = 0;
break;
}
tsleep(&sc->ec_gencount, PZERO, "ecgpe", slp_ival);
gen_count = sc->ec_gencount;
}
/*
* We finished waiting for the GPE and it never arrived. Try to
* read the register once and trust whatever value we got. This is
* the best we can do at this point. Then, force polled mode on
* since this system doesn't appear to generate GPEs.
* the best we can do at this point.
*/
if (Status != AE_OK) {
if (Status != AE_OK)
Status = EcCheckStatus(sc, "sleep_end", Event);
device_printf(sc->ec_dev,
"wait timed out (%sresponse), forcing polled mode\n",
Status == AE_OK ? "" : "no ");
ec_polled_mode = TRUE;
}
}
if (!need_poll && no_intr > 10) {
device_printf(sc->ec_dev,
"not getting interrupts, switched to polled mode\n");
ec_polled_mode = 1;
}
if (Status != AE_OK)
CTR0(KTR_ACPI, "error: ec wait timed out");
@ -933,6 +924,14 @@ EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
return (AE_BAD_PARAMETER);
}
/*
* Ensure empty input buffer before issuing command.
* Use generation count of zero to force a quick check.
*/
status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, 0);
if (ACPI_FAILURE(status))
return (status);
/* Run the command and wait for the chosen event. */
CTR1(KTR_ACPI, "ec running command %#x", cmd);
gen_count = sc->ec_gencount;
@ -955,24 +954,31 @@ EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
{
ACPI_STATUS status;
u_int gen_count;
int retry;
ACPI_SERIAL_ASSERT(ec);
CTR1(KTR_ACPI, "ec read from %#x", Address);
status = EcCommand(sc, EC_COMMAND_READ);
if (ACPI_FAILURE(status))
return (status);
for (retry = 0; retry < 2; retry++) {
status = EcCommand(sc, EC_COMMAND_READ);
if (ACPI_FAILURE(status))
return (status);
gen_count = sc->ec_gencount;
EC_SET_DATA(sc, Address);
status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
if (ACPI_FAILURE(status)) {
device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
return (status);
gen_count = sc->ec_gencount;
EC_SET_DATA(sc, Address);
status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
if (ACPI_FAILURE(status)) {
if (EcCheckStatus(sc, "retr_check",
EC_EVENT_INPUT_BUFFER_EMPTY) == AE_OK)
continue;
else
break;
}
*Data = EC_GET_DATA(sc);
return (AE_OK);
}
*Data = EC_GET_DATA(sc);
return (AE_OK);
device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
return (status);
}
static ACPI_STATUS
@ -992,7 +998,7 @@ EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 Data)
EC_SET_DATA(sc, Address);
status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
if (ACPI_FAILURE(status)) {
device_printf(sc->ec_dev, "EcRead: failed waiting for sent address\n");
device_printf(sc->ec_dev, "EcWrite: failed waiting for sent address\n");
return (status);
}