Module Name: src
Committed By: riastradh
Date: Tue Jul 18 10:03:47 UTC 2023
Modified Files:
src/sys/dev/acpi: acpi_ec.c
Log Message:
acpiec(4): Sprinkle comments.
Note where this code is abusing cv_wait and needs a loop to handle
spurious wakeups.
No functional change intended.
To generate a diff of this commit:
cvs rdiff -u -r1.89 -r1.90 src/sys/dev/acpi/acpi_ec.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/acpi/acpi_ec.c
diff -u src/sys/dev/acpi/acpi_ec.c:1.89 src/sys/dev/acpi/acpi_ec.c:1.90
--- src/sys/dev/acpi/acpi_ec.c:1.89 Tue Jul 18 10:03:35 2023
+++ src/sys/dev/acpi/acpi_ec.c Tue Jul 18 10:03:46 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_ec.c,v 1.89 2023/07/18 10:03:35 riastradh Exp $ */
+/* $NetBSD: acpi_ec.c,v 1.90 2023/07/18 10:03:46 riastradh Exp $ */
/*-
* Copyright (c) 2007 Joerg Sonnenberger <jo...@netbsd.org>.
@@ -57,7 +57,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_ec.c,v 1.89 2023/07/18 10:03:35 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_ec.c,v 1.90 2023/07/18 10:03:46 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_acpi_ec.h"
@@ -694,6 +694,11 @@ acpiec_read(device_t dv, uint8_t addr, u
return AE_ERROR;
}
} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
+ /*
+ * XXX while (sc->sc_state != EC_STATE_FREE)
+ * cv_timedwait(...),
+ * plus deadline
+ */
mutex_exit(&sc->sc_mtx);
acpiec_unlock(dv);
aprint_error_dev(dv,
@@ -756,6 +761,11 @@ acpiec_write(device_t dv, uint8_t addr,
return AE_ERROR;
}
} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
+ /*
+ * XXX while (sc->sc_state != EC_STATE_FREE)
+ * cv_timedwait(...),
+ * plus deadline
+ */
mutex_exit(&sc->sc_mtx);
acpiec_unlock(dv);
aprint_error_dev(dv,
@@ -869,13 +879,21 @@ acpiec_gpe_query(void *arg)
int i;
loop:
+ /*
+ * Wait until the EC sends an SCI requesting a query.
+ *
+ * XXX This needs to be `while', not `if'.
+ */
mutex_enter(&sc->sc_mtx);
-
if (sc->sc_got_sci == false)
cv_wait(&sc->sc_cv_sci, &sc->sc_mtx);
DPRINTF(ACPIEC_DEBUG_QUERY, sc, "SCI query requested\n");
mutex_exit(&sc->sc_mtx);
+ /*
+ * EC wants to submit a query to us. Exclude concurrent reads
+ * and writes while we handle it.
+ */
acpiec_lock(dv);
mutex_enter(&sc->sc_mtx);
@@ -893,6 +911,7 @@ loop:
}
DPRINTF(ACPIEC_DEBUG_QUERY, sc, "SCI polling timeout\n");
+ /* XXX while (sc->sc_state != EC_STATE_FREE) cv_wait(...) */
cv_wait(&sc->sc_cv, &sc->sc_mtx);
done:
@@ -951,17 +970,14 @@ acpiec_gpe_state_machine(device_t dv)
case EC_STATE_QUERY_VAL:
if ((reg & EC_STATUS_OBF) == 0)
break; /* Nothing of interest here. */
-
sc->sc_cur_val = acpiec_read_data(sc);
sc->sc_state = EC_STATE_FREE;
-
cv_signal(&sc->sc_cv);
break;
case EC_STATE_READ:
if ((reg & EC_STATUS_IBF) != 0)
break; /* Nothing of interest here. */
-
acpiec_write_command(sc, EC_COMMAND_READ);
sc->sc_state = EC_STATE_READ_ADDR;
break;
@@ -969,7 +985,6 @@ acpiec_gpe_state_machine(device_t dv)
case EC_STATE_READ_ADDR:
if ((reg & EC_STATUS_IBF) != 0)
break; /* Nothing of interest here. */
-
acpiec_write_data(sc, sc->sc_cur_addr);
sc->sc_state = EC_STATE_READ_VAL;
break;
@@ -979,14 +994,12 @@ acpiec_gpe_state_machine(device_t dv)
break; /* Nothing of interest here. */
sc->sc_cur_val = acpiec_read_data(sc);
sc->sc_state = EC_STATE_FREE;
-
cv_signal(&sc->sc_cv);
break;
case EC_STATE_WRITE:
if ((reg & EC_STATUS_IBF) != 0)
break; /* Nothing of interest here. */
-
acpiec_write_command(sc, EC_COMMAND_WRITE);
sc->sc_state = EC_STATE_WRITE_ADDR;
break;
@@ -1003,7 +1016,6 @@ acpiec_gpe_state_machine(device_t dv)
break; /* Nothing of interest here. */
sc->sc_state = EC_STATE_FREE;
cv_signal(&sc->sc_cv);
-
acpiec_write_data(sc, sc->sc_cur_val);
break;
@@ -1014,10 +1026,15 @@ acpiec_gpe_state_machine(device_t dv)
cv_signal(&sc->sc_cv_sci);
}
break;
+
default:
panic("invalid state");
}
+ /*
+ * In case GPE interrupts are broken, poll once per tick for EC
+ * status updates while a transaction is still pending.
+ */
if (sc->sc_state != EC_STATE_FREE) {
DPRINTF(ACPIEC_DEBUG_INTR, sc, "schedule callout\n");
callout_schedule(&sc->sc_pseudo_intr, 1);
