From: <viro@www.linux.org.uk>
References to slave ports of mux added to struct parport.
parport_daisy_init() doesn't go through parport_announce_port() for mux
slaves anymore; parport_annouce_port() deals with found ones itself. Error
handling sanitized, races on unregistration fixed.
---
drivers/parport/daisy.c | 20 +++++++++-
drivers/parport/share.c | 94 ++++++++++++++++++++++++++++++------------------
include/linux/parport.h | 1
3 files changed, 79 insertions(+), 36 deletions(-)
diff -puN drivers/parport/daisy.c~parport-06-refcounting-fixes drivers/parport/daisy.c
--- 25/drivers/parport/daisy.c~parport-06-refcounting-fixes 2004-02-18 23:43:57.000000000 -0800
+++ 25-akpm/drivers/parport/daisy.c 2004-02-18 23:43:57.000000000 -0800
@@ -80,6 +80,7 @@ static struct parport *clone_parport (st
extra->portnum = real->portnum;
extra->physport = real;
extra->muxport = muxport;
+ real->slaves[muxport-1] = extra;
}
return extra;
@@ -94,7 +95,9 @@ int parport_daisy_init (struct parport *
static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
int num_ports;
int i;
+ int last_try = 0;
+again:
/* Because this is called before any other devices exist,
* we don't have to claim exclusive access. */
@@ -127,7 +130,7 @@ int parport_daisy_init (struct parport *
/* Analyse that port too. We won't recurse
forever because of the 'port->muxport < 0'
test above. */
- parport_announce_port (extra);
+ parport_daisy_init(extra);
}
}
@@ -149,6 +152,21 @@ int parport_daisy_init (struct parport *
kfree (deviceid);
}
+ if (!detected && !last_try) {
+ /* No devices were detected. Perhaps they are in some
+ funny state; let's try to reset them and see if
+ they wake up. */
+ parport_daisy_fini (port);
+ parport_write_control (port, PARPORT_CONTROL_SELECT);
+ udelay (50);
+ parport_write_control (port,
+ PARPORT_CONTROL_SELECT |
+ PARPORT_CONTROL_INIT);
+ udelay (50);
+ last_try = 1;
+ goto again;
+ }
+
return detected;
}
diff -puN drivers/parport/share.c~parport-06-refcounting-fixes drivers/parport/share.c
--- 25/drivers/parport/share.c~parport-06-refcounting-fixes 2004-02-18 23:43:57.000000000 -0800
+++ 25-akpm/drivers/parport/share.c 2004-02-18 23:43:57.000000000 -0800
@@ -413,22 +413,11 @@ struct parport *parport_register_port(un
void parport_announce_port (struct parport *port)
{
+ int i;
#ifdef CONFIG_PARPORT_1284
/* Analyse the IEEE1284.3 topology of the port. */
- if (parport_daisy_init (port) == 0) {
- /* No devices were detected. Perhaps they are in some
- funny state; let's try to reset them and see if
- they wake up. */
- parport_daisy_fini (port);
- parport_write_control (port, PARPORT_CONTROL_SELECT);
- udelay (50);
- parport_write_control (port,
- PARPORT_CONTROL_SELECT |
- PARPORT_CONTROL_INIT);
- udelay (50);
- parport_daisy_init (port);
- }
+ parport_daisy_init(port);
#endif
down(®istration_lock);
@@ -447,13 +436,48 @@ void parport_announce_port (struct parpo
portlist_tail = port;
if (!portlist)
portlist = port;
+ for (i = 1; i < 3; i++) {
+ struct parport *slave = port->slaves[i-1];
+ if (slave) {
+ portlist_tail->next = slave;
+ portlist_tail = slave;
+ }
+ }
spin_unlock_irq(&parportlist_lock);
- /* Let drivers know that a new port has arrived. */
+ /* Let drivers know that new port(s) has arrived. */
attach_driver_chain (port);
+ for (i = 1; i < 3; i++) {
+ struct parport *slave = port->slaves[i-1];
+ if (slave)
+ attach_driver_chain(slave);
+ }
up(®istration_lock);
}
+static void unlink_from_list(struct parport *port)
+{
+ struct parport *p;
+ spin_lock(&parportlist_lock);
+ /* We are protected from other people changing the list, but
+ * they can still see it (using parport_enumerate). So be
+ * careful about the order of writes.. */
+ if (portlist == port) {
+ if ((portlist = port->next) == NULL)
+ portlist_tail = NULL;
+ } else {
+ for (p = portlist; (p != NULL) && (p->next != port);
+ p=p->next);
+ if (p) {
+ if ((p->next = port->next) == NULL)
+ portlist_tail = p;
+ }
+ else printk (KERN_WARNING
+ "%s not found in port list!\n", port->name);
+ }
+ spin_unlock(&parportlist_lock);
+}
+
/**
* parport_unregister_port - deregister a parallel port
* @port: parallel port to deregister
@@ -475,41 +499,41 @@ void parport_announce_port (struct parpo
void parport_unregister_port(struct parport *port)
{
- struct parport *p;
+ int i;
down(®istration_lock);
- port->ops = &dead_ops;
/* Spread the word. */
detach_driver_chain (port);
#ifdef CONFIG_PARPORT_1284
/* Forget the IEEE1284.3 topology of the port. */
- parport_daisy_fini (port);
+ parport_daisy_fini(port);
+ for (i = 1; i < 3; i++) {
+ struct parport *slave = port->slaves[i-1];
+ if (!slave)
+ continue;
+ detach_driver_chain(slave);
+ parport_daisy_fini(slave);
+ }
#endif
- spin_lock(&parportlist_lock);
-
- /* We are protected from other people changing the list, but
- * they can still see it (using parport_enumerate). So be
- * careful about the order of writes.. */
- if (portlist == port) {
- if ((portlist = port->next) == NULL)
- portlist_tail = NULL;
- } else {
- for (p = portlist; (p != NULL) && (p->next != port);
- p=p->next);
- if (p) {
- if ((p->next = port->next) == NULL)
- portlist_tail = p;
- }
- else printk (KERN_WARNING
- "%s not found in port list!\n", port->name);
+ port->ops = &dead_ops;
+ unlink_from_list(port);
+ for (i = 1; i < 3; i++) {
+ struct parport *slave = port->slaves[i-1];
+ if (slave)
+ unlink_from_list(slave);
}
- spin_unlock(&parportlist_lock);
+
up(®istration_lock);
/* Yes, parport_enumerate _is_ unsafe. Don't use it. */
+ for (i = 1; i < 3; i++) {
+ struct parport *slave = port->slaves[i-1];
+ if (slave)
+ parport_put_port(slave);
+ }
parport_put_port (port);
}
diff -puN include/linux/parport.h~parport-06-refcounting-fixes include/linux/parport.h
--- 25/include/linux/parport.h~parport-06-refcounting-fixes 2004-02-18 23:43:57.000000000 -0800
+++ 25-akpm/include/linux/parport.h 2004-02-18 23:43:57.000000000 -0800
@@ -313,6 +313,7 @@ struct parport {
atomic_t ref_count;
struct list_head full_list;
+ struct parport *slaves[3];
};
#define DEFAULT_SPIN_TIME 500 /* us */
_