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Close a race condition by passing status retrieved via a non-SCI call

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to EcGpeQueryHandler on to any waiting threads through the softc.  Similar
behavior was in the original version.

Also:
* Merge EcQuery into EcGpeQueryHandler to simplify locking
* Hold EcLock from the initial read of the CSR down to the wakeup or
  until after the query command has been processed.
* ec_gpebit only needs to be a UINT8
This commit is contained in:
Nate Lawson 2003-07-20 21:11:32 +00:00
parent d5c96e1341
commit 3a371f32b3
1 changed files with 32 additions and 43 deletions
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75
sys/dev/acpica/acpi_ec.c
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@ -247,7 +247,8 @@ typedef struct {
struct acpi_ec_softc {
device_t ec_dev;
ACPI_HANDLE ec_handle;
UINT32 ec_gpebit;
UINT8 ec_gpebit;
UINT8 ec_csrvalue;
int ec_data_rid;
struct resource *ec_data_res;
@ -262,7 +263,7 @@ struct acpi_ec_softc {
int ec_glk;
int ec_glkhandle;
struct mtx ec_mtx;
UINT32 ec_polldelay;
int ec_polldelay;
};
/*
@ -321,7 +322,6 @@ static ACPI_STATUS EcSpaceHandler(UINT32 Function,
UINT32 width, ACPI_INTEGER *Value,
void *Context, void *RegionContext);
static ACPI_STATUS EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event);
static ACPI_STATUS EcQuery(struct acpi_ec_softc *sc, UINT8 *Data);
static ACPI_STATUS EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
static ACPI_STATUS EcRead(struct acpi_ec_softc *sc, UINT8 Address,
UINT8 *Data);
@ -590,29 +590,6 @@ acpi_ec_attach(device_t dev)
return (errval);
}
static ACPI_STATUS
EcQuery(struct acpi_ec_softc *sc, UINT8 *Data)
{
ACPI_STATUS Status;
Status = EcLock(sc);
if (ACPI_FAILURE(Status))
return (Status);
/*
* Send a query command to the EC to find out which _Qxx call it
* wants to make. This command clears the SCI bit and also the
* interrupt source since we are edge-triggered.
*/
Status = EcCommand(sc, EC_COMMAND_QUERY);
if (ACPI_SUCCESS(Status))
*Data = EC_GET_DATA(sc);
EcUnlock(sc);
return (Status);
}
static void
EcGpeQueryHandler(void *Context)
{
@ -625,32 +602,39 @@ EcGpeQueryHandler(void *Context)
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
Status = EcLock(sc);
if (ACPI_FAILURE(Status)) {
ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
"GpeQuery lock error: %s\n", AcpiFormatException(Status));
return;
}
/*
* Check status for EC_SCI.
*
* Bail out if the EC_SCI bit of the status register is not set.
* Note that this function should only be called when
* this bit is set (polling is used to detect IBE/OBF events).
*
* We don't acquire the global lock here but do protect against other
* running commands (read/write/query) by grabbing ec_mtx.
* If the EC_SCI bit of the status register is not set, then pass
* it along to any potential waiters as it may be an IBE/OBF event.
*/
mtx_lock(&sc->ec_mtx);
EcStatus = EC_GET_CSR(sc);
mtx_unlock(&sc->ec_mtx);
if ((EcStatus & EC_EVENT_SCI) == 0) {
/* If it's not an SCI, wakeup the EcWaitEvent sleep. */
wakeup(&sc->ec_polldelay);
sc->ec_csrvalue = EcStatus;
wakeup(&sc->ec_csrvalue);
EcUnlock(sc);
goto re_enable;
}
/* Find out why the EC is signaling us. */
Status = EcQuery(sc, &Data);
/*
* Send a query command to the EC to find out which _Qxx call it
* wants to make. This command clears the SCI bit and also the
* interrupt source since we are edge-triggered.
*/
Status = EcCommand(sc, EC_COMMAND_QUERY);
if (ACPI_FAILURE(Status)) {
EcUnlock(sc);
ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
"GPE query failed - %s\n", AcpiFormatException(Status));
goto re_enable;
}
Data = EC_GET_DATA(sc);
EcUnlock(sc);
/* Ignore the value for "no outstanding event". (13.3.5) */
if (Data == 0)
@ -770,7 +754,7 @@ EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event)
{
EC_STATUS EcStatus;
ACPI_STATUS Status;
UINT32 i, period;
int i, period, retval;
mtx_assert(&sc->ec_mtx, MA_OWNED);
Status = AE_NO_HARDWARE_RESPONSE;
@ -812,13 +796,18 @@ EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event)
* for completion, sleeping for chunks of 10 ms.
*/
if (Status != AE_OK) {
retval = -1;
for (i = 0; i < EC_POLL_TIMEOUT / 10; i++) {
EcStatus = EC_GET_CSR(sc);
if (retval != 0)
EcStatus = EC_GET_CSR(sc);
else
EcStatus = sc->ec_csrvalue;
if (EVENT_READY(Event, EcStatus)) {
Status = AE_OK;
break;
}
msleep(&sc->ec_polldelay, &sc->ec_mtx, PZERO, "ecpoll", 10/*ms*/);
retval = msleep(&sc->ec_csrvalue, &sc->ec_mtx, PZERO, "ecpoll",
10/*ms*/);
}
}