[PATCH 7/11] serio no recursion

From: Dmitry Torokhov
Date: Fri Jun 18 2004 - 04:02:47 EST


===================================================================


ChangeSet@xxxxxx, 2004-06-18 00:09:46-05:00, dtor_core@xxxxxxxxxxxxx
Input: allow serio drivers to create children ports and register these
ports for them in serio core to avoid having recursion in connect
methods.

Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>


drivers/input/mouse/psmouse-base.c | 75 ++++++++----
drivers/input/mouse/psmouse.h | 16 --
drivers/input/mouse/synaptics.c | 27 +---
drivers/input/serio/serio.c | 215 ++++++++++++++++++++++++++++---------
include/linux/serio.h | 4
5 files changed, 231 insertions(+), 106 deletions(-)


===================================================================



diff -Nru a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
--- a/drivers/input/mouse/psmouse-base.c 2004-06-18 03:16:50 -05:00
+++ b/drivers/input/mouse/psmouse-base.c 2004-06-18 03:16:50 -05:00
@@ -670,16 +670,15 @@

static void psmouse_disconnect(struct serio *serio)
{
- struct psmouse *psmouse = serio->private;
+ struct psmouse *psmouse, *parent;

+ psmouse = serio->private;
psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);

- if (psmouse->ptport) {
- if (psmouse->ptport->deactivate)
- psmouse->ptport->deactivate(psmouse);
- __serio_unregister_port(psmouse->ptport->serio); /* we have serio_sem */
- kfree(psmouse->ptport);
- psmouse->ptport = NULL;
+ if (serio->parent && (serio->type & SERIO_TYPE) == SERIO_PS_PSTHRU) {
+ parent = serio->parent->private;
+ if (parent->pt_deactivate)
+ parent->pt_deactivate(parent);
}

if (psmouse->disconnect)
@@ -698,14 +697,17 @@
*/
static void psmouse_connect(struct serio *serio, struct serio_driver *drv)
{
- struct psmouse *psmouse;
+ struct psmouse *psmouse, *parent = NULL;

if ((serio->type & SERIO_TYPE) != SERIO_8042 &&
(serio->type & SERIO_TYPE) != SERIO_PS_PSTHRU)
return;

+ if (serio->parent && (serio->type & SERIO_TYPE) == SERIO_PS_PSTHRU)
+ parent = serio->parent->private;
+
if (!(psmouse = kmalloc(sizeof(struct psmouse), GFP_KERNEL)))
- return;
+ goto out;

memset(psmouse, 0, sizeof(struct psmouse));

@@ -721,14 +723,14 @@
if (serio_open(serio, drv)) {
kfree(psmouse);
serio->private = NULL;
- return;
+ goto out;
}

if (psmouse_probe(psmouse) < 0) {
serio_close(serio);
kfree(psmouse);
serio->private = NULL;
- return;
+ goto out;
}

psmouse->type = psmouse_extensions(psmouse, psmouse_max_proto, 1);
@@ -757,20 +759,36 @@

psmouse_initialize(psmouse);

- if (psmouse->ptport) {
- printk(KERN_INFO "serio: %s port at %s\n", psmouse->ptport->serio->name, psmouse->phys);
- __serio_register_port(psmouse->ptport->serio); /* we have serio_sem */
- if (psmouse->ptport->activate)
- psmouse->ptport->activate(psmouse);
- }
+ if (parent && parent->pt_activate)
+ parent->pt_activate(parent);

- psmouse_activate(psmouse);
+ /*
+ * OK, the device is ready, we just need to activate it (turn the
+ * stream mode on). But if mouse has a pass-through port we don't
+ * want to do it yet to not disturb child detection.
+ * The child will activate this port when it's ready.
+ */
+
+ if (serio->child) {
+ /*
+ * Nothing to be done here, serio core will detect that
+ * the driver set serio->child and will register it for us.
+ */
+ printk(KERN_INFO "serio: %s port at %s\n", serio->child->name, psmouse->phys);
+ } else
+ psmouse_activate(psmouse);
+
+out:
+ /* If this is a pass-through port the parent awaits to be activated */
+ if (parent)
+ psmouse_activate(parent);
}


static int psmouse_reconnect(struct serio *serio)
{
struct psmouse *psmouse = serio->private;
+ struct psmouse *parent = NULL;
struct serio_driver *drv = serio->drv;

if (!drv || !psmouse) {
@@ -792,16 +810,19 @@
*/
psmouse_initialize(psmouse);

- if (psmouse->ptport) {
- if (psmouse_reconnect(psmouse->ptport->serio)) {
- __serio_unregister_port(psmouse->ptport->serio);
- __serio_register_port(psmouse->ptport->serio);
- if (psmouse->ptport->activate)
- psmouse->ptport->activate(psmouse);
- }
- }
+ if (serio->parent && (serio->type & SERIO_TYPE) == SERIO_PS_PSTHRU)
+ parent = serio->parent->private;
+
+ if (parent && parent->pt_activate)
+ parent->pt_activate(parent);
+
+ if (!serio->child)
+ psmouse_activate(psmouse);
+
+ /* If this is a pass-through port the parent waits to be activated */
+ if (parent)
+ psmouse_activate(parent);

- psmouse_activate(psmouse);
return 0;
}

diff -Nru a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
--- a/drivers/input/mouse/psmouse.h 2004-06-18 03:16:50 -05:00
+++ b/drivers/input/mouse/psmouse.h 2004-06-18 03:16:50 -05:00
@@ -34,21 +34,10 @@
PSMOUSE_FULL_PACKET
} psmouse_ret_t;

-struct psmouse;
-
-struct psmouse_ptport {
- struct serio *serio;
- struct psmouse *parent;
-
- void (*activate)(struct psmouse *parent);
- void (*deactivate)(struct psmouse *parent);
-};
-
struct psmouse {
void *private;
struct input_dev dev;
struct serio *serio;
- struct psmouse_ptport *ptport;
char *vendor;
char *name;
unsigned char cmdbuf[8];
@@ -66,9 +55,12 @@
char phys[32];
unsigned long flags;

- psmouse_ret_t (*protocol_handler)(struct psmouse *psmouse, struct pt_regs *regs);
+ psmouse_ret_t (*protocol_handler)(struct psmouse *psmouse, struct pt_regs *regs);
int (*reconnect)(struct psmouse *psmouse);
void (*disconnect)(struct psmouse *psmouse);
+
+ void (*pt_activate)(struct psmouse *psmouse);
+ void (*pt_deactivate)(struct psmouse *psmouse);
};

#define PSMOUSE_PS2 1
diff -Nru a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
--- a/drivers/input/mouse/synaptics.c 2004-06-18 03:16:50 -05:00
+++ b/drivers/input/mouse/synaptics.c 2004-06-18 03:16:50 -05:00
@@ -212,14 +212,14 @@
/*****************************************************************************
* Synaptics pass-through PS/2 port support
****************************************************************************/
-static int synaptics_pt_write(struct serio *port, unsigned char c)
+static int synaptics_pt_write(struct serio *serio, unsigned char c)
{
- struct psmouse_ptport *ptport = port->port_data;
+ struct psmouse *parent = serio->parent->private;
char rate_param = SYN_PS_CLIENT_CMD; /* indicates that we want pass-through port */

- if (psmouse_sliced_command(ptport->parent, c))
+ if (psmouse_sliced_command(parent, c))
return -1;
- if (psmouse_command(ptport->parent, &rate_param, PSMOUSE_CMD_SETRATE))
+ if (psmouse_command(parent, &rate_param, PSMOUSE_CMD_SETRATE))
return -1;
return 0;
}
@@ -248,7 +248,7 @@

static void synaptics_pt_activate(struct psmouse *psmouse)
{
- struct psmouse *child = psmouse->ptport->serio->private;
+ struct psmouse *child = psmouse->serio->child->private;

/* adjust the touchpad to child's choice of protocol */
if (child && child->type >= PSMOUSE_GENPS) {
@@ -259,30 +259,25 @@

static void synaptics_pt_create(struct psmouse *psmouse)
{
- struct psmouse_ptport *port;
struct serio *serio;

- port = kmalloc(sizeof(struct psmouse_ptport), GFP_KERNEL);
serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
- if (!port || !serio) {
+ if (!serio) {
printk(KERN_ERR "synaptics: not enough memory to allocate pass-through port\n");
return;
}

- memset(port, 0, sizeof(struct psmouse_ptport));
memset(serio, 0, sizeof(struct serio));

serio->type = SERIO_PS_PSTHRU;
strlcpy(serio->name, "Synaptics pass-through", sizeof(serio->name));
strlcpy(serio->phys, "synaptics-pt/serio0", sizeof(serio->name));
serio->write = synaptics_pt_write;
- serio->port_data = port;
+ serio->parent = psmouse->serio;

- port->serio = serio;
- port->parent = psmouse;
- port->activate = synaptics_pt_activate;
+ psmouse->pt_activate = synaptics_pt_activate;

- psmouse->ptport = port;
+ psmouse->serio->child = serio;
}

/*****************************************************************************
@@ -477,8 +472,8 @@
if (unlikely(priv->pkt_type == SYN_NEWABS))
priv->pkt_type = synaptics_detect_pkt_type(psmouse);

- if (psmouse->ptport && psmouse->ptport->serio->drv && synaptics_is_pt_packet(psmouse->packet))
- synaptics_pass_pt_packet(psmouse->ptport->serio, psmouse->packet);
+ if (psmouse->serio->child && psmouse->serio->child->drv && synaptics_is_pt_packet(psmouse->packet))
+ synaptics_pass_pt_packet(psmouse->serio->child, psmouse->packet);
else
synaptics_process_packet(psmouse);

diff -Nru a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
--- a/drivers/input/serio/serio.c 2004-06-18 03:16:50 -05:00
+++ b/drivers/input/serio/serio.c 2004-06-18 03:16:50 -05:00
@@ -44,10 +44,8 @@
EXPORT_SYMBOL(serio_interrupt);
EXPORT_SYMBOL(serio_register_port);
EXPORT_SYMBOL(serio_register_port_delayed);
-EXPORT_SYMBOL(__serio_register_port);
EXPORT_SYMBOL(serio_unregister_port);
EXPORT_SYMBOL(serio_unregister_port_delayed);
-EXPORT_SYMBOL(__serio_unregister_port);
EXPORT_SYMBOL(serio_register_driver);
EXPORT_SYMBOL(serio_unregister_driver);
EXPORT_SYMBOL(serio_open);
@@ -59,17 +57,28 @@
static LIST_HEAD(serio_list);
static LIST_HEAD(serio_driver_list);

-/* serio_find_driver() must be called with serio_sem down. */
+static void serio_find_driver(struct serio *serio);
+static void serio_create_port(struct serio *serio);
+static void serio_destroy_port(struct serio *serio);
+static void serio_connect_port(struct serio *serio, struct serio_driver *drv);
+static void serio_reconnect_port(struct serio *serio);
+static void serio_disconnect_port(struct serio *serio);
+
+static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
+{
+ drv->connect(serio, drv);
+
+ return serio->drv != NULL;
+}

+/* serio_find_driver() must be called with serio_sem down. */
static void serio_find_driver(struct serio *serio)
{
struct serio_driver *drv;

- list_for_each_entry(drv, &serio_driver_list, node) {
- if (serio->drv)
+ list_for_each_entry(drv, &serio_driver_list, node)
+ if (serio_bind_driver(serio, drv))
break;
- drv->connect(serio, drv);
- }
}

/*
@@ -145,23 +154,22 @@

switch (event->type) {
case SERIO_REGISTER_PORT :
- __serio_register_port(event->serio);
+ serio_create_port(event->serio);
+ serio_connect_port(event->serio, NULL);
break;

case SERIO_UNREGISTER_PORT :
- __serio_unregister_port(event->serio);
+ serio_disconnect_port(event->serio);
+ serio_destroy_port(event->serio);
break;

case SERIO_RECONNECT :
- if (event->serio->drv && event->serio->drv->reconnect)
- if (event->serio->drv->reconnect(event->serio) == 0)
- break;
- /* reconnect failed - fall through to rescan */
+ serio_reconnect_port(event->serio);
+ break;

case SERIO_RESCAN :
- if (event->serio->drv)
- event->serio->drv->disconnect(event->serio);
- serio_find_driver(event->serio);
+ serio_disconnect_port(event->serio);
+ serio_connect_port(event->serio, NULL);
break;
default:
break;
@@ -216,6 +224,118 @@
* Serio port operations
*/

+static void serio_create_port(struct serio *serio)
+{
+ spin_lock_init(&serio->lock);
+ list_add_tail(&serio->node, &serio_list);
+}
+
+/*
+ * serio_destroy_port() completes deregistration process and removes
+ * port from the system
+ */
+static void serio_destroy_port(struct serio *serio)
+{
+ struct serio_driver *drv = serio->drv;
+ unsigned long flags;
+
+ serio_remove_pending_events(serio);
+ list_del_init(&serio->node);
+
+ if (drv)
+ drv->disconnect(serio);
+
+ if (serio->parent) {
+ spin_lock_irqsave(&serio->parent->lock, flags);
+ serio->parent->child = NULL;
+ spin_unlock_irqrestore(&serio->parent->lock, flags);
+ }
+
+ kfree(serio);
+}
+
+/*
+ * serio_connect_port() tries to bind the port and possible all its
+ * children to appropriate drivers. If driver passed in the function will not
+ * try otehr drivers when binding parent port.
+ */
+static void serio_connect_port(struct serio *serio, struct serio_driver *drv)
+{
+ WARN_ON(serio->drv);
+ WARN_ON(serio->child);
+
+ if (drv)
+ serio_bind_driver(serio, drv);
+ else
+ serio_find_driver(serio);
+
+ /* Ok, now bind children, if any */
+ while (serio->child) {
+ serio = serio->child;
+
+ WARN_ON(serio->drv);
+ WARN_ON(serio->child);
+
+ serio_create_port(serio);
+
+ /*
+ * With children we just _prefer_ passed in driver,
+ * but we will try other options in case preferred
+ * is not the one
+ */
+ if (!drv || !serio_bind_driver(serio, drv))
+ serio_find_driver(serio);
+ }
+}
+
+/*
+ *
+ */
+static void serio_reconnect_port(struct serio *serio)
+{
+ do {
+ if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
+ serio_disconnect_port(serio);
+ serio_connect_port(serio, NULL);
+ /* Ok, old children are now gone, we are done */
+ break;
+ }
+ serio = serio->child;
+ } while (serio);
+}
+
+/*
+ * serio_disconnect_port() unbinds a port from its driver. As a side effect
+ * all child ports are unbound and destroyed.
+ */
+static void serio_disconnect_port(struct serio *serio)
+{
+ struct serio_driver *drv = serio->drv;
+ struct serio *s;
+
+ if (serio->child) {
+ /*
+ * Children ports should be disconnected and destroyed
+ * first, staring with the leaf one, since we don't want
+ * to do recursion
+ */
+ do {
+ s = serio->child;
+ } while (s->child);
+
+ while (s != serio) {
+ s = s->parent;
+ serio_destroy_port(s->child);
+ }
+ }
+
+ /*
+ * Ok, no children left, now disconnect this port
+ */
+ if (drv)
+ drv->disconnect(serio);
+}
+
void serio_rescan(struct serio *serio)
{
serio_queue_event(serio, SERIO_RESCAN);
@@ -229,7 +349,8 @@
void serio_register_port(struct serio *serio)
{
down(&serio_sem);
- __serio_register_port(serio);
+ serio_create_port(serio);
+ serio_connect_port(serio, NULL);
up(&serio_sem);
}

@@ -243,22 +364,11 @@
serio_queue_event(serio, SERIO_REGISTER_PORT);
}

-/*
- * Should only be called directly if serio_sem has already been taken,
- * for example when unregistering a serio from other input device's
- * connect() function.
- */
-void __serio_register_port(struct serio *serio)
-{
- spin_lock_init(&serio->lock);
- list_add_tail(&serio->node, &serio_list);
- serio_find_driver(serio);
-}
-
void serio_unregister_port(struct serio *serio)
{
down(&serio_sem);
- __serio_unregister_port(serio);
+ serio_disconnect_port(serio);
+ serio_destroy_port(serio);
up(&serio_sem);
}

@@ -272,32 +382,33 @@
serio_queue_event(serio, SERIO_UNREGISTER_PORT);
}

-/*
- * Should only be called directly if serio_sem has already been taken,
- * for example when unregistering a serio from other input device's
- * disconnect() function.
- */
-void __serio_unregister_port(struct serio *serio)
-{
- serio_remove_pending_events(serio);
- list_del_init(&serio->node);
- if (serio->drv)
- serio->drv->disconnect(serio);
- kfree(serio);
-}

/*
* Serio driver operations
*/

+
void serio_register_driver(struct serio_driver *drv)
{
struct serio *serio;
+
down(&serio_sem);
+
list_add_tail(&drv->node, &serio_driver_list);
- list_for_each_entry(serio, &serio_list, node)
- if (!serio->drv)
- drv->connect(serio, drv);
+
+start_over:
+ list_for_each_entry(serio, &serio_list, node) {
+ if (!serio->drv) {
+ serio_connect_port(serio, drv);
+ /*
+ * if new child appeared then the list is changed,
+ * we need to start over
+ */
+ if (serio->child)
+ goto start_over;
+ }
+ }
+
up(&serio_sem);
}

@@ -306,13 +417,19 @@
struct serio *serio;

down(&serio_sem);
+
list_del_init(&drv->node);

+start_over:
list_for_each_entry(serio, &serio_list, node) {
- if (serio->drv == drv)
- drv->disconnect(serio);
- serio_find_driver(serio);
+ if (serio->drv == drv) {
+ serio_disconnect_port(serio);
+ serio_connect_port(serio, NULL);
+ /* we could've deleted some ports, restart */
+ goto start_over;
+ }
}
+
up(&serio_sem);
}

diff -Nru a/include/linux/serio.h b/include/linux/serio.h
--- a/include/linux/serio.h 2004-06-18 03:16:50 -05:00
+++ b/include/linux/serio.h 2004-06-18 03:16:50 -05:00
@@ -40,6 +40,8 @@
int (*open)(struct serio *);
void (*close)(struct serio *);

+ struct serio *parent, *child;
+
struct serio_driver *drv; /* Accessed from interrupt, writes must be protected by serio_lock */

struct list_head node;
@@ -68,10 +70,8 @@

void serio_register_port(struct serio *serio);
void serio_register_port_delayed(struct serio *serio);
-void __serio_register_port(struct serio *serio);
void serio_unregister_port(struct serio *serio);
void serio_unregister_port_delayed(struct serio *serio);
-void __serio_unregister_port(struct serio *serio);
void serio_register_driver(struct serio_driver *drv);
void serio_unregister_driver(struct serio_driver *drv);

-
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