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path: root/drivers/parport/share.c
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Diffstat (limited to 'drivers/parport/share.c')
-rw-r--r--drivers/parport/share.c26
1 files changed, 23 insertions, 3 deletions
diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index 7b4ee33c1935..d6920ebeabcd 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c
@@ -230,6 +230,18 @@ static int port_check(struct device *dev, void *dev_drv)
return 0;
}
+/*
+ * Iterates through all the devices connected to the bus and return 1
+ * if the device is a parallel port.
+ */
+
+static int port_detect(struct device *dev, void *dev_drv)
+{
+ if (is_parport(dev))
+ return 1;
+ return 0;
+}
+
/**
* parport_register_driver - register a parallel port device driver
* @drv: structure describing the driver
@@ -266,9 +278,6 @@ static int port_check(struct device *dev, void *dev_drv)
int __parport_register_driver(struct parport_driver *drv, struct module *owner,
const char *mod_name)
{
- if (list_empty(&portlist))
- get_lowlevel_driver();
-
if (drv->devmodel) {
/* using device model */
int ret;
@@ -282,6 +291,15 @@ int __parport_register_driver(struct parport_driver *drv, struct module *owner,
if (ret)
return ret;
+ /*
+ * check if bus has any parallel port registered, if
+ * none is found then load the lowlevel driver.
+ */
+ ret = bus_for_each_dev(&parport_bus_type, NULL, NULL,
+ port_detect);
+ if (!ret)
+ get_lowlevel_driver();
+
mutex_lock(&registration_lock);
if (drv->match_port)
bus_for_each_dev(&parport_bus_type, NULL, drv,
@@ -292,6 +310,8 @@ int __parport_register_driver(struct parport_driver *drv, struct module *owner,
drv->devmodel = false;
+ if (list_empty(&portlist))
+ get_lowlevel_driver();
mutex_lock(&registration_lock);
list_for_each_entry(port, &portlist, list)
drv->attach(port);