msm: smd_tty: Handle error conditions in open operation
The smd_tty driver assumes the Linux TTY Framework will call the close
operation when the open operation returns an error. This assumption is
not valid with the recent tty_port refactoring.
The tty_port layer internally maintains a reference count of number of
times a tty device is opened. The tty_port layer invokes "activate"
operation when a tty device is opened for the first time and "shutdown"
operation when a tty device is closed for the last time.
Update the smd_tty driver to release any resource that is allocated when
the open operation hits an error scenario. Remove the redundant open_count
in the smd_tty driver.
CRs-Fixed: 470184
Change-Id: I50a126497b235bed895e01748c77d8a0660261b3
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
diff --git a/arch/arm/mach-msm/smd_tty.c b/arch/arm/mach-msm/smd_tty.c
index 8a2c23f..0b270b7 100644
--- a/arch/arm/mach-msm/smd_tty.c
+++ b/arch/arm/mach-msm/smd_tty.c
@@ -63,7 +63,6 @@
struct tty_port port;
struct device *device_ptr;
struct wake_lock wake_lock;
- int open_count;
struct tasklet_struct tty_tsklt;
struct timer_list buf_req_timer;
struct completion ch_allocated;
@@ -333,112 +332,106 @@
mutex_lock(&smd_tty_lock);
tty->driver_data = info;
- if (info->open_count++ == 0) {
- peripheral = smd_edge_to_subsystem(smd_tty[n].smd->edge);
- if (peripheral) {
- info->pil = subsystem_get(peripheral);
- if (IS_ERR(info->pil)) {
- SMD_TTY_INFO(
- "%s failed on smd_tty device :%s subsystem_get failed for %s",
- __func__, smd_tty[n].smd->port_name,
- peripheral);
- /*
- * Sleep, inorder to reduce the frequency of
- * retry by user-space modules and to avoid
- * possible watchdog bite.
- */
- msleep((smd_tty[n].open_wait * 1000));
- res = PTR_ERR(info->pil);
- goto out;
- }
-
- /* Wait for the modem SMSM to be inited for the SMD
- * Loopback channel to be allocated at the modem. Since
- * the wait need to be done atmost once, using msleep
- * doesn't degrade the performance.
- */
- if (n == LOOPBACK_IDX) {
- if (!is_modem_smsm_inited())
- msleep(5000);
- smsm_change_state(SMSM_APPS_STATE,
- 0, SMSM_SMD_LOOPBACK);
- msleep(100);
- }
-
+ peripheral = smd_edge_to_subsystem(smd_tty[n].smd->edge);
+ if (peripheral) {
+ info->pil = subsystem_get(peripheral);
+ if (IS_ERR(info->pil)) {
+ SMD_TTY_INFO(
+ "%s failed on smd_tty device :%s subsystem_get failed for %s",
+ __func__, smd_tty[n].smd->port_name,
+ peripheral);
/*
- * Wait for a channel to be allocated so we know
- * the modem is ready enough.
+ * Sleep, inorder to reduce the frequency of
+ * retry by user-space modules and to avoid
+ * possible watchdog bite.
*/
- if (smd_tty[n].open_wait) {
- res = wait_for_completion_interruptible_timeout(
+ msleep((smd_tty[n].open_wait * 1000));
+ res = PTR_ERR(info->pil);
+ goto out;
+ }
+
+ /* Wait for the modem SMSM to be inited for the SMD
+ * Loopback channel to be allocated at the modem. Since
+ * the wait need to be done atmost once, using msleep
+ * doesn't degrade the performance.
+ */
+ if (n == LOOPBACK_IDX) {
+ if (!is_modem_smsm_inited())
+ msleep(5000);
+ smsm_change_state(SMSM_APPS_STATE,
+ 0, SMSM_SMD_LOOPBACK);
+ msleep(100);
+ }
+
+ /*
+ * Wait for a channel to be allocated so we know
+ * the modem is ready enough.
+ */
+ if (smd_tty[n].open_wait) {
+ res = wait_for_completion_interruptible_timeout(
&info->ch_allocated,
msecs_to_jiffies(smd_tty[n].open_wait *
1000));
- if (res == 0) {
- SMD_TTY_INFO(
- "Timed out waiting for SMD channel %s",
- smd_tty[n].smd->port_name);
- res = -ETIMEDOUT;
- goto release_pil;
- } else if (res < 0) {
- SMD_TTY_INFO(
- "Error waiting for SMD channel %s : %d\n",
- smd_tty[n].smd->port_name, res);
- goto release_pil;
- }
-
- res = 0;
- }
- }
-
- tasklet_init(&info->tty_tsklt, smd_tty_read,
- (unsigned long)info);
- wake_lock_init(&info->wake_lock, WAKE_LOCK_SUSPEND,
- smd_tty[n].smd->port_name);
- scnprintf(info->ra_wake_lock_name,
- MAX_RA_WAKE_LOCK_NAME_LEN,
- "SMD_TTY_%s_RA", smd_tty[n].smd->port_name);
- wake_lock_init(&info->ra_wake_lock, WAKE_LOCK_SUSPEND,
- info->ra_wake_lock_name);
- if (!info->ch) {
- res = smd_named_open_on_edge(smd_tty[n].smd->port_name,
- smd_tty[n].smd->edge,
- &info->ch, info,
- smd_tty_notify);
- if (res < 0) {
+ if (res == 0) {
SMD_TTY_INFO(
- "%s: %s open failed %d\n",
- __func__, smd_tty[n].smd->port_name,
- res);
- goto release_pil;
- }
-
- res = wait_event_interruptible_timeout(
- info->ch_opened_wait_queue,
- info->is_open, (2 * HZ));
- if (res == 0)
+ "Timed out waiting for SMD channel %s",
+ smd_tty[n].smd->port_name);
res = -ETIMEDOUT;
- if (res < 0) {
+ goto release_pil;
+ } else if (res < 0) {
SMD_TTY_INFO(
- "%s: wait for %s smd_open failed %d\n",
- __func__, smd_tty[n].smd->port_name,
- res);
+ "Error waiting for SMD channel %s : %d\n",
+ smd_tty[n].smd->port_name, res);
goto release_pil;
}
- res = 0;
- SMD_TTY_INFO("%s with PID %u opened port %s",
- current->comm, current->pid,
- smd_tty[n].smd->port_name);
}
}
+ tasklet_init(&info->tty_tsklt, smd_tty_read, (unsigned long)info);
+ wake_lock_init(&info->wake_lock, WAKE_LOCK_SUSPEND,
+ smd_tty[n].smd->port_name);
+ scnprintf(info->ra_wake_lock_name, MAX_RA_WAKE_LOCK_NAME_LEN,
+ "SMD_TTY_%s_RA", smd_tty[n].smd->port_name);
+ wake_lock_init(&info->ra_wake_lock, WAKE_LOCK_SUSPEND,
+ info->ra_wake_lock_name);
+
+ res = smd_named_open_on_edge(smd_tty[n].smd->port_name,
+ smd_tty[n].smd->edge, &info->ch, info,
+ smd_tty_notify);
+ if (res < 0) {
+ SMD_TTY_INFO("%s: %s open failed %d\n",
+ __func__, smd_tty[n].smd->port_name, res);
+ goto release_wl_tl;
+ }
+
+ res = wait_event_interruptible_timeout(info->ch_opened_wait_queue,
+ info->is_open, (2 * HZ));
+ if (res == 0)
+ res = -ETIMEDOUT;
+ if (res < 0) {
+ SMD_TTY_INFO("%s: wait for %s smd_open failed %d\n",
+ __func__, smd_tty[n].smd->port_name, res);
+ goto close_ch;
+ }
+ SMD_TTY_INFO("%s with PID %u opened port %s",
+ current->comm, current->pid, smd_tty[n].smd->port_name);
+ smd_disable_read_intr(info->ch);
+ mutex_unlock(&smd_tty_lock);
+ return 0;
+
+close_ch:
+ smd_close(info->ch);
+ info->ch = NULL;
+
+release_wl_tl:
+ tasklet_kill(&info->tty_tsklt);
+ wake_lock_destroy(&info->wake_lock);
+ wake_lock_destroy(&info->ra_wake_lock);
+
release_pil:
- if (res < 0)
- subsystem_put(info->pil);
- else
- smd_disable_read_intr(info->ch);
+ subsystem_put(info->pil);
out:
mutex_unlock(&smd_tty_lock);
@@ -458,26 +451,25 @@
}
mutex_lock(&smd_tty_lock);
- if (--info->open_count == 0) {
- spin_lock_irqsave(&info->reset_lock, flags);
- info->is_open = 0;
- spin_unlock_irqrestore(&info->reset_lock, flags);
- if (tty) {
- tasklet_kill(&info->tty_tsklt);
- wake_lock_destroy(&info->wake_lock);
- wake_lock_destroy(&info->ra_wake_lock);
- }
- SMD_TTY_INFO("%s with PID %u closed port %s",
- current->comm, current->pid,
- info->smd->port_name);
- tty->driver_data = 0;
- del_timer(&info->buf_req_timer);
- if (info->ch) {
- smd_close(info->ch);
- info->ch = 0;
- subsystem_put(info->pil);
- }
- }
+
+ spin_lock_irqsave(&info->reset_lock, flags);
+ info->is_open = 0;
+ spin_unlock_irqrestore(&info->reset_lock, flags);
+
+ tasklet_kill(&info->tty_tsklt);
+ wake_lock_destroy(&info->wake_lock);
+ wake_lock_destroy(&info->ra_wake_lock);
+
+ SMD_TTY_INFO("%s with PID %u closed port %s",
+ current->comm, current->pid,
+ info->smd->port_name);
+ tty->driver_data = NULL;
+ del_timer(&info->buf_req_timer);
+
+ smd_close(info->ch);
+ info->ch = NULL;
+ subsystem_put(info->pil);
+
mutex_unlock(&smd_tty_lock);
tty_kref_put(tty);
}