Module Name: src
Committed By: thorpej
Date: Sun May 16 21:03:38 UTC 2021
Modified Files:
src/sys/dev/i2c [thorpej-i2c-spi-conf]: i2c.c
Log Message:
- Set D_MCLOSE in the iic_cdevsw so that we get a d_close call for
each close so that the module ref counting works properly.
- Rearrange things a little to avoid holding the iic_mtx a long as
previously done.
To generate a diff of this commit:
cvs rdiff -u -r1.78.2.3 -r1.78.2.4 src/sys/dev/i2c/i2c.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/i2c/i2c.c
diff -u src/sys/dev/i2c/i2c.c:1.78.2.3 src/sys/dev/i2c/i2c.c:1.78.2.4
--- src/sys/dev/i2c/i2c.c:1.78.2.3 Sun May 16 04:40:08 2021
+++ src/sys/dev/i2c/i2c.c Sun May 16 21:03:38 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: i2c.c,v 1.78.2.3 2021/05/16 04:40:08 thorpej Exp $ */
+/* $NetBSD: i2c.c,v 1.78.2.4 2021/05/16 21:03:38 thorpej Exp $ */
/*-
* Copyright (c) 2021 The NetBSD Foundation, Inc.
@@ -69,7 +69,7 @@
#endif
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: i2c.c,v 1.78.2.3 2021/05/16 04:40:08 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: i2c.c,v 1.78.2.4 2021/05/16 21:03:38 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -115,13 +115,6 @@ static dev_type_open(iic_open);
static dev_type_close(iic_close);
static dev_type_ioctl(iic_ioctl);
-int iic_init(void);
-
-kmutex_t iic_mtx;
-int iic_refcnt;
-
-ONCE_DECL(iic_once);
-
const struct cdevsw iic_cdevsw = {
.d_open = iic_open,
.d_close = iic_close,
@@ -134,11 +127,16 @@ const struct cdevsw iic_cdevsw = {
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
- .d_flag = D_OTHER
+ .d_flag = D_OTHER | D_MCLOSE,
};
static void iic_smbus_intr_thread(void *);
+static kmutex_t iic_mtx;
+static int iic_refcnt;
+static bool iic_unloading;
+static ONCE_DECL(iic_once);
+
static struct i2c_device_link *
iic_devslot_lookup(struct iic_softc *sc, i2c_addr_t addr)
{
@@ -928,22 +926,43 @@ iic_use_direct_match(const struct i2c_at
static int
iic_open(dev_t dev, int flag, int fmt, lwp_t *l)
{
- struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));
+ struct iic_softc *sc;
mutex_enter(&iic_mtx);
- if (sc == NULL) {
+
+ if (iic_unloading) {
mutex_exit(&iic_mtx);
return ENXIO;
}
+
+ /* Hold a refrence while we look up the softc. */
+ if (iic_refcnt == INT_MAX) {
+ mutex_exit(&iic_mtx);
+ return EBUSY;
+ }
iic_refcnt++;
+
mutex_exit(&iic_mtx);
+ sc = device_lookup_private(&iic_cd, minor(dev));
+
+ if (sc == NULL) {
+ mutex_enter(&iic_mtx);
+ iic_refcnt--;
+ mutex_exit(&iic_mtx);
+ return ENXIO;
+ }
+
return 0;
}
static int
iic_close(dev_t dev, int flag, int fmt, lwp_t *l)
{
+ struct iic_softc *sc = device_lookup_private(&iic_cd, minor(dev));;
+
+ KASSERT(iic_refcnt != 0);
+ KASSERT(sc != NULL);
mutex_enter(&iic_mtx);
iic_refcnt--;
@@ -1037,7 +1056,7 @@ MODULE(MODULE_CLASS_DRIVER, iic, "i2cexe
#include "ioconf.c"
#endif
-int
+static int
iic_init(void)
{
@@ -1084,19 +1103,26 @@ iic_modcmd(modcmd_t cmd, void *opaque)
mutex_exit(&iic_mtx);
return EBUSY;
}
+ iic_unloading = true;
+ mutex_exit(&iic_mtx);
#ifdef _MODULE
error = config_fini_component(cfdriver_ioconf_iic,
cfattach_ioconf_iic, cfdata_ioconf_iic);
if (error != 0) {
+ mutex_enter(&iic_mtx);
+ iic_unloading = false;
mutex_exit(&iic_mtx);
break;
}
error = devsw_detach(NULL, &iic_cdevsw);
- if (error != 0)
+ if (error != 0) {
config_init_component(cfdriver_ioconf_iic,
cfattach_ioconf_iic, cfdata_ioconf_iic);
+ mutex_enter(&iic_mtx);
+ iic_unloading = false;
+ mutex_exit(&iic_mtx);
+ }
#endif
- mutex_exit(&iic_mtx);
break;
default:
error = ENOTTY;
