Input: psmouse - attempt to re-synchronize mouse every 5 seconds

This should help driver to deal vith KVMs that reset mice when
switching between boxes.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 252 insertions, 64 deletions

diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 4d5ecc04c5b6..7665fd9ce559 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -54,10 +54,14 @@ static unsigned int psmouse_smartscroll = 1;
 module_param_named(smartscroll, psmouse_smartscroll, bool, 0644);
 MODULE_PARM_DESC(smartscroll, "Logitech Smartscroll autorepeat, 1 = enabled (default), 0 = disabled.");
 
-static unsigned int psmouse_resetafter;
+static unsigned int psmouse_resetafter = 5;
 module_param_named(resetafter, psmouse_resetafter, uint, 0644);
 MODULE_PARM_DESC(resetafter, "Reset device after so many bad packets (0 = never).");
 
+static unsigned int psmouse_resync_time = 5;
+module_param_named(resync_time, psmouse_resync_time, uint, 0644);
+MODULE_PARM_DESC(resync_time, "How long can mouse stay idle before forcing resync (in seconds, 0 = never).");
+
 PSMOUSE_DEFINE_ATTR(protocol, S_IWUSR | S_IRUGO,
                         NULL,
                         psmouse_attr_show_protocol, psmouse_attr_set_protocol);
@@ -70,12 +74,16 @@ PSMOUSE_DEFINE_ATTR(resolution, S_IWUSR | S_IRUGO,
 PSMOUSE_DEFINE_ATTR(resetafter, S_IWUSR | S_IRUGO,
                         (void *) offsetof(struct psmouse, resetafter),
                         psmouse_show_int_attr, psmouse_set_int_attr);
+PSMOUSE_DEFINE_ATTR(resync_time, S_IWUSR | S_IRUGO,
+                        (void *) offsetof(struct psmouse, resync_time),
+                        psmouse_show_int_attr, psmouse_set_int_attr);
 
 static struct attribute *psmouse_attributes[] = {
         &psmouse_attr_protocol.dattr.attr,
         &psmouse_attr_rate.dattr.attr,
         &psmouse_attr_resolution.dattr.attr,
         &psmouse_attr_resetafter.dattr.attr,
+        &psmouse_attr_resync_time.dattr.attr,
         NULL
 };
 
@@ -98,6 +106,8 @@ __obsolete_setup("psmouse_rate=");
  */
 static DECLARE_MUTEX(psmouse_sem);
 
+static struct workqueue_struct *kpsmoused_wq;
+
 struct psmouse_protocol {
         enum psmouse_type type;
         char *name;
@@ -178,15 +188,79 @@ static psmouse_ret_t psmouse_process_byte(struct psmouse *psmouse, struct pt_reg
 }
 
 /*
- * psmouse_interrupt() handles incoming characters, either gathering them into
- * packets or passing them to the command routine as command output.
+ * __psmouse_set_state() sets new psmouse state and resets all flags.
+ */
+
+static inline void __psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
+{
+        psmouse->state = new_state;
+        psmouse->pktcnt = psmouse->out_of_sync = 0;
+        psmouse->ps2dev.flags = 0;
+        psmouse->last = jiffies;
+}
+
+
+/*
+ * psmouse_set_state() sets new psmouse state and resets all flags and
+ * counters while holding serio lock so fighting with interrupt handler
+ * is not a concern.
+ */
+
+static void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
+{
+        serio_pause_rx(psmouse->ps2dev.serio);
+        __psmouse_set_state(psmouse, new_state);
+        serio_continue_rx(psmouse->ps2dev.serio);
+}
+
+/*
+ * psmouse_handle_byte() processes one byte of the input data stream
+ * by calling corresponding protocol handler.
+ */
+
+static int psmouse_handle_byte(struct psmouse *psmouse, struct pt_regs *regs)
+{
+        psmouse_ret_t rc = psmouse->protocol_handler(psmouse, regs);
+
+        switch (rc) {
+                case PSMOUSE_BAD_DATA:
+                        if (psmouse->state == PSMOUSE_ACTIVATED) {
+                                printk(KERN_WARNING "psmouse.c: %s at %s lost sync at byte %d\n",
+                                        psmouse->name, psmouse->phys, psmouse->pktcnt);
+                                if (++psmouse->out_of_sync == psmouse->resetafter) {
+                                        __psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+                                        printk(KERN_NOTICE "psmouse.c: issuing reconnect request\n");
+                                        serio_reconnect(psmouse->ps2dev.serio);
+                                        return -1;
+                                }
+                        }
+                        psmouse->pktcnt = 0;
+                        break;
+
+                case PSMOUSE_FULL_PACKET:
+                        psmouse->pktcnt = 0;
+                        if (psmouse->out_of_sync) {
+                                psmouse->out_of_sync = 0;
+                                printk(KERN_NOTICE "psmouse.c: %s at %s - driver resynched.\n",
+                                        psmouse->name, psmouse->phys);
+                        }
+                        break;
+
+                case PSMOUSE_GOOD_DATA:
+                        break;
+        }
+        return 0;
+}
+
+/*
+ * psmouse_interrupt() handles incoming characters, either passing them
+ * for normal processing or gathering them as command response.
  */
 
 static irqreturn_t psmouse_interrupt(struct serio *serio,
                 unsigned char data, unsigned int flags, struct pt_regs *regs)
 {
         struct psmouse *psmouse = serio_get_drvdata(serio);
-        psmouse_ret_t rc;
 
         if (psmouse->state == PSMOUSE_IGNORE)
                 goto out;
@@ -208,67 +282,58 @@ static irqreturn_t psmouse_interrupt(struct serio *serio,
                 if  (ps2_handle_response(&psmouse->ps2dev, data))
                         goto out;
 
-        if (psmouse->state == PSMOUSE_INITIALIZING)
+        if (psmouse->state <= PSMOUSE_RESYNCING)
                 goto out;
 
         if (psmouse->state == PSMOUSE_ACTIVATED &&
             psmouse->pktcnt && time_after(jiffies, psmouse->last + HZ/2)) {
-                printk(KERN_WARNING "psmouse.c: %s at %s lost synchronization, throwing %d bytes away.\n",
+                printk(KERN_INFO "psmouse.c: %s at %s lost synchronization, throwing %d bytes away.\n",
                        psmouse->name, psmouse->phys, psmouse->pktcnt);
-                psmouse->pktcnt = 0;
+                psmouse->badbyte = psmouse->packet[0];
+                __psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
+                queue_work(kpsmoused_wq, &psmouse->resync_work);
+                goto out;
         }
 
-        psmouse->last = jiffies;
         psmouse->packet[psmouse->pktcnt++] = data;
-
-        if (psmouse->packet[0] == PSMOUSE_RET_BAT) {
+/*
+ * Check if this is a new device announcement (0xAA 0x00)
+ */
+        if (unlikely(psmouse->packet[0] == PSMOUSE_RET_BAT && psmouse->pktcnt <= 2)) {
                 if (psmouse->pktcnt == 1)
                         goto out;
 
-                if (psmouse->pktcnt == 2) {
-                        if (psmouse->packet[1] == PSMOUSE_RET_ID) {
-                                psmouse->state = PSMOUSE_IGNORE;
-                                serio_reconnect(serio);
-                                goto out;
-                        }
-                        if (psmouse->type == PSMOUSE_SYNAPTICS) {
-                                /* neither 0xAA nor 0x00 are valid first bytes
-                                 * for a packet in absolute mode
-                                 */
-                                psmouse->pktcnt = 0;
-                                goto out;
-                        }
+                if (psmouse->packet[1] == PSMOUSE_RET_ID) {
+                        __psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+                        serio_reconnect(serio);
+                        goto out;
                 }
-        }
-
-        rc = psmouse->protocol_handler(psmouse, regs);
+/*
+ * Not a new device, try processing first byte normally
+ */
+                psmouse->pktcnt = 1;
+                if (psmouse_handle_byte(psmouse, regs))
+                        goto out;
 
-        switch (rc) {
-                case PSMOUSE_BAD_DATA:
-                        printk(KERN_WARNING "psmouse.c: %s at %s lost sync at byte %d\n",
-                                psmouse->name, psmouse->phys, psmouse->pktcnt);
-                        psmouse->pktcnt = 0;
+                psmouse->packet[psmouse->pktcnt++] = data;
+        }
 
-                        if (++psmouse->out_of_sync == psmouse->resetafter) {
-                                psmouse->state = PSMOUSE_IGNORE;
-                                printk(KERN_NOTICE "psmouse.c: issuing reconnect request\n");
-                                serio_reconnect(psmouse->ps2dev.serio);
-                        }
-                        break;
+/*
+ * See if we need to force resync because mouse was idle for too long
+ */
+        if (psmouse->state == PSMOUSE_ACTIVATED &&
+            psmouse->pktcnt == 1 && psmouse->resync_time &&
+            time_after(jiffies, psmouse->last + psmouse->resync_time * HZ)) {
+                psmouse->badbyte = psmouse->packet[0];
+                __psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
+                queue_work(kpsmoused_wq, &psmouse->resync_work);
+                goto out;
+        }
 
-                case PSMOUSE_FULL_PACKET:
-                        psmouse->pktcnt = 0;
-                        if (psmouse->out_of_sync) {
-                                psmouse->out_of_sync = 0;
-                                printk(KERN_NOTICE "psmouse.c: %s at %s - driver resynched.\n",
-                                        psmouse->name, psmouse->phys);
-                        }
-                        break;
+        psmouse->last = jiffies;
+        psmouse_handle_byte(psmouse, regs);
 
-                case PSMOUSE_GOOD_DATA:
-                        break;
-        }
-out:
+ out:
         return IRQ_HANDLED;
 }
 
@@ -752,21 +817,6 @@ static void psmouse_initialize(struct psmouse *psmouse)
 }
 
 /*
- * psmouse_set_state() sets new psmouse state and resets all flags and
- * counters while holding serio lock so fighting with interrupt handler
- * is not a concern.
- */
-
-static void psmouse_set_state(struct psmouse *psmouse, enum psmouse_state new_state)
-{
-        serio_pause_rx(psmouse->ps2dev.serio);
-        psmouse->state = new_state;
-        psmouse->pktcnt = psmouse->out_of_sync = 0;
-        psmouse->ps2dev.flags = 0;
-        serio_continue_rx(psmouse->ps2dev.serio);
-}
-
-/*
  * psmouse_activate() enables the mouse so that we get motion reports from it.
  */
 
@@ -794,6 +844,111 @@ static void psmouse_deactivate(struct psmouse *psmouse)
         psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
 }
 
+/*
+ * psmouse_poll() - default poll hanlder. Everyone except for ALPS uses it.
+ */
+
+static int psmouse_poll(struct psmouse *psmouse)
+{
+        return ps2_command(&psmouse->ps2dev, psmouse->packet,
+                           PSMOUSE_CMD_POLL | (psmouse->pktsize << 8));
+}
+
+
+/*
+ * psmouse_resync() attempts to re-validate current protocol.
+ */
+
+static void psmouse_resync(void *p)
+{
+        struct psmouse *psmouse = p, *parent = NULL;
+        struct serio *serio = psmouse->ps2dev.serio;
+        psmouse_ret_t rc = PSMOUSE_GOOD_DATA;
+        int failed = 0, enabled = 0;
+        int i;
+
+        down(&psmouse_sem);
+
+        if (psmouse->state != PSMOUSE_RESYNCING)
+                goto out;
+
+        if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
+                parent = serio_get_drvdata(serio->parent);
+                psmouse_deactivate(parent);
+        }
+
+/*
+ * Some mice don't ACK commands sent while they are in the middle of
+ * transmitting motion packet. To avoid delay we use ps2_sendbyte()
+ * instead of ps2_command() which would wait for 200ms for an ACK
+ * that may never come.
+ * As an additional quirk ALPS touchpads may not only forget to ACK
+ * disable command but will stop reporting taps, so if we see that
+ * mouse at least once ACKs disable we will do full reconnect if ACK
+ * is missing.
+ */
+        psmouse->num_resyncs++;
+
+        if (ps2_sendbyte(&psmouse->ps2dev, PSMOUSE_CMD_DISABLE, 20)) {
+                if (psmouse->num_resyncs < 3 || psmouse->acks_disable_command)
+                        failed = 1;
+        } else
+                psmouse->acks_disable_command = 1;
+
+/*
+ * Poll the mouse. If it was reset the packet will be shorter than
+ * psmouse->pktsize and ps2_command will fail. We do not expect and
+ * do not handle scenario when mouse "upgrades" its protocol while
+ * disconnected since it would require additional delay. If we ever
+ * see a mouse that does it we'll adjust the code.
+ */
+        if (!failed) {
+                if (psmouse->poll(psmouse))
+                        failed = 1;
+                else {
+                        psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
+                        for (i = 0; i < psmouse->pktsize; i++) {
+                                psmouse->pktcnt++;
+                                rc = psmouse->protocol_handler(psmouse, NULL);
+                                if (rc != PSMOUSE_GOOD_DATA)
+                                        break;
+                        }
+                        if (rc != PSMOUSE_FULL_PACKET)
+                                failed = 1;
+                        psmouse_set_state(psmouse, PSMOUSE_RESYNCING);
+                }
+        }
+/*
+ * Now try to enable mouse. We try to do that even if poll failed and also
+ * repeat our attempts 5 times, otherwise we may be left out with disabled
+ * mouse.
+ */
+        for (i = 0; i < 5; i++) {
+                if (!ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_ENABLE)) {
+                        enabled = 1;
+                        break;
+                }
+                msleep(200);
+        }
+
+        if (!enabled) {
+                printk(KERN_WARNING "psmouse.c: failed to re-enable mouse on %s\n",
+                        psmouse->ps2dev.serio->phys);
+                failed = 1;
+        }
+
+        if (failed) {
+                psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+                printk(KERN_INFO "psmouse.c: resync failed, issuing reconnect request\n");
+                serio_reconnect(serio);
+        } else
+                psmouse_set_state(psmouse, PSMOUSE_ACTIVATED);
+
+        if (parent)
+                psmouse_activate(parent);
+ out:
+        up(&psmouse_sem);
+}
 
 /*
  * psmouse_cleanup() resets the mouse into power-on state.
@@ -822,6 +977,11 @@ static void psmouse_disconnect(struct serio *serio)
 
         psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
 
+        /* make sure we don't have a resync in progress */
+        up(&psmouse_sem);
+        flush_workqueue(kpsmoused_wq);
+        down(&psmouse_sem);
+
         if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
                 parent = serio_get_drvdata(serio->parent);
                 psmouse_deactivate(parent);
@@ -859,6 +1019,7 @@ static int psmouse_switch_protocol(struct psmouse *psmouse, struct psmouse_proto
 
         psmouse->set_rate = psmouse_set_rate;
         psmouse->set_resolution = psmouse_set_resolution;
+        psmouse->poll = psmouse_poll;
         psmouse->protocol_handler = psmouse_process_byte;
         psmouse->pktsize = 3;
 
@@ -874,6 +1035,23 @@ static int psmouse_switch_protocol(struct psmouse *psmouse, struct psmouse_proto
         else
                 psmouse->type = psmouse_extensions(psmouse, psmouse_max_proto, 1);
 
+        /*
+         * If mouse's packet size is 3 there is no point in polling the
+         * device in hopes to detect protocol reset - we won't get less
+         * than 3 bytes response anyhow.
+         */
+        if (psmouse->pktsize == 3)
+                psmouse->resync_time = 0;
+
+        /*
+         * Some smart KVMs fake response to POLL command returning just
+         * 3 bytes and messing up our resync logic, so if initial poll
+         * fails we won't try polling the device anymore. Hopefully
+         * such KVM will maintain initially selected protocol.
+         */
+        if (psmouse->resync_time && psmouse->poll(psmouse))
+                psmouse->resync_time = 0;
+
         sprintf(psmouse->devname, "%s %s %s",
                 psmouse_protocol_by_type(psmouse->type)->name, psmouse->vendor, psmouse->name);
 
@@ -914,6 +1092,7 @@ static int psmouse_connect(struct serio *serio, struct serio_driver *drv)
                 goto out;
 
         ps2_init(&psmouse->ps2dev, serio);
+        INIT_WORK(&psmouse->resync_work, psmouse_resync, psmouse);
         psmouse->dev = input_dev;
         sprintf(psmouse->phys, "%s/input0", serio->phys);
 
@@ -934,6 +1113,7 @@ static int psmouse_connect(struct serio *serio, struct serio_driver *drv)
         psmouse->rate = psmouse_rate;
         psmouse->resolution = psmouse_resolution;
         psmouse->resetafter = psmouse_resetafter;
+        psmouse->resync_time = parent ? 0 : psmouse_resync_time;
         psmouse->smartscroll = psmouse_smartscroll;
 
         psmouse_switch_protocol(psmouse, NULL);
@@ -1278,13 +1458,21 @@ static int psmouse_get_maxproto(char *buffer, struct kernel_param *kp)
 
 static int __init psmouse_init(void)
 {
+        kpsmoused_wq = create_singlethread_workqueue("kpsmoused");
+        if (!kpsmoused_wq) {
+                printk(KERN_ERR "psmouse: failed to create kpsmoused workqueue\n");
+                return -ENOMEM;
+        }
+
         serio_register_driver(&psmouse_drv);
+
         return 0;
 }
 
 static void __exit psmouse_exit(void)
 {
         serio_unregister_driver(&psmouse_drv);
+        destroy_workqueue(kpsmoused_wq);
 }
 
 module_init(psmouse_init);