USB: ssu100: rework logic for TIOCMIWAIT

Rework the logic for TIOCMIWAIT to use wait_event_interruptible.

This also adds support for TIOCGICOUNT.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 111 insertions, 35 deletions

diff --git a/drivers/usb/serial/ssu100.c b/drivers/usb/serial/ssu100.c
index ad5f9ae40687..e244491b1a0d 100644
--- a/drivers/usb/serial/ssu100.c
+++ b/drivers/usb/serial/ssu100.c
@@ -80,6 +80,7 @@ struct ssu100_port_private {
         u8 shadowMSR;
         wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
         unsigned short max_packet_size;
+        struct async_icount icount;
 };
 
 static void ssu100_release(struct usb_serial *serial)
@@ -330,11 +331,8 @@ static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port)
         }
 
         spin_lock_irqsave(&priv->status_lock, flags);
-        priv->shadowLSR = data[0]  & (UART_LSR_OE | UART_LSR_PE |
-                                      UART_LSR_FE | UART_LSR_BI);
-
-        priv->shadowMSR = data[1]  & (UART_MSR_CTS | UART_MSR_DSR |
-                                      UART_MSR_RI | UART_MSR_DCD);
+        priv->shadowLSR = data[0];
+        priv->shadowMSR = data[1];
         spin_unlock_irqrestore(&priv->status_lock, flags);
 
         kfree(data);
@@ -379,11 +377,51 @@ static int get_serial_info(struct usb_serial_port *port,
         return 0;
 }
 
+static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
+{
+        struct ssu100_port_private *priv = usb_get_serial_port_data(port);
+        struct async_icount prev, cur;
+        unsigned long flags;
+
+        spin_lock_irqsave(&priv->status_lock, flags);
+        prev = priv->icount;
+        spin_unlock_irqrestore(&priv->status_lock, flags);
+
+        while (1) {
+                wait_event_interruptible(priv->delta_msr_wait,
+                                         ((priv->icount.rng != prev.rng) ||
+                                          (priv->icount.dsr != prev.dsr) ||
+                                          (priv->icount.dcd != prev.dcd) ||
+                                          (priv->icount.cts != prev.cts)));
+
+                if (signal_pending(current))
+                        return -ERESTARTSYS;
+
+                spin_lock_irqsave(&priv->status_lock, flags);
+                cur = priv->icount;
+                spin_unlock_irqrestore(&priv->status_lock, flags);
+
+                if ((prev.rng == cur.rng) &&
+                    (prev.dsr == cur.dsr) &&
+                    (prev.dcd == cur.dcd) &&
+                    (prev.cts == cur.cts))
+                        return -EIO;
+
+                if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||
+                    (arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||
+                    (arg & TIOCM_CD  && (prev.dcd != cur.dcd)) ||
+                    (arg & TIOCM_CTS && (prev.cts != cur.cts)))
+                        return 0;
+        }
+        return 0;
+}
+
 static int ssu100_ioctl(struct tty_struct *tty, struct file *file,
                     unsigned int cmd, unsigned long arg)
 {
         struct usb_serial_port *port = tty->driver_data;
         struct ssu100_port_private *priv = usb_get_serial_port_data(port);
+        void __user *user_arg = (void __user *)arg;
 
         dbg("%s cmd 0x%04x", __func__, cmd);
 
@@ -393,28 +431,28 @@ static int ssu100_ioctl(struct tty_struct *tty, struct file *file,
                                        (struct serial_struct __user *) arg);
 
         case TIOCMIWAIT:
-                while (priv != NULL) {
-                        u8 prevMSR = priv->shadowMSR & SERIAL_MSR_MASK;
-                        interruptible_sleep_on(&priv->delta_msr_wait);
-                        /* see if a signal did it */
-                        if (signal_pending(current))
-                                return -ERESTARTSYS;
-                        else {
-                                u8 diff = (priv->shadowMSR & SERIAL_MSR_MASK) ^ prevMSR;
-                                if (!diff)
-                                        return -EIO; /* no change => error */
-
-                                /* Return 0 if caller wanted to know about
-                                   these bits */
-
-                                if (((arg & TIOCM_RNG) && (diff & UART_MSR_RI)) ||
-                                    ((arg & TIOCM_DSR) && (diff & UART_MSR_DSR)) ||
-                                    ((arg & TIOCM_CD) && (diff & UART_MSR_DCD)) ||
-                                    ((arg & TIOCM_CTS) && (diff & UART_MSR_CTS)))
-                                        return 0;
-                        }
-                }
+                return wait_modem_info(port, arg);
+
+        case TIOCGICOUNT:
+        {
+                struct serial_icounter_struct icount;
+                struct async_icount cnow = priv->icount;
+                memset(&icount, 0, sizeof(icount));
+                icount.cts = cnow.cts;
+                icount.dsr = cnow.dsr;
+                icount.rng = cnow.rng;
+                icount.dcd = cnow.dcd;
+                icount.rx = cnow.rx;
+                icount.tx = cnow.tx;
+                icount.frame = cnow.frame;
+                icount.overrun = cnow.overrun;
+                icount.parity = cnow.parity;
+                icount.brk = cnow.brk;
+                icount.buf_overrun = cnow.buf_overrun;
+                if (copy_to_user(user_arg, &icount, sizeof(icount)))
+                        return -EFAULT;
                 return 0;
+        }
 
         default:
                 break;
@@ -541,6 +579,50 @@ static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
         mutex_unlock(&port->serial->disc_mutex);
 }
 
+static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
+{
+        struct ssu100_port_private *priv = usb_get_serial_port_data(port);
+        unsigned long flags;
+
+        spin_lock_irqsave(&priv->status_lock, flags);
+        priv->shadowMSR = msr;
+        spin_unlock_irqrestore(&priv->status_lock, flags);
+
+        if (msr & UART_MSR_ANY_DELTA) {
+                /* update input line counters */
+                if (msr & UART_MSR_DCTS)
+                        priv->icount.cts++;
+                if (msr & UART_MSR_DDSR)
+                        priv->icount.dsr++;
+                if (msr & UART_MSR_DDCD)
+                        priv->icount.dcd++;
+                if (msr & UART_MSR_TERI)
+                        priv->icount.rng++;
+                wake_up_interruptible(&priv->delta_msr_wait);
+        }
+}
+
+static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr)
+{
+        struct ssu100_port_private *priv = usb_get_serial_port_data(port);
+        unsigned long flags;
+
+        spin_lock_irqsave(&priv->status_lock, flags);
+        priv->shadowLSR = lsr;
+        spin_unlock_irqrestore(&priv->status_lock, flags);
+
+        if (lsr & UART_LSR_BRK_ERROR_BITS) {
+                if (lsr & UART_LSR_BI)
+                        priv->icount.brk++;
+                if (lsr & UART_LSR_FE)
+                        priv->icount.frame++;
+                if (lsr & UART_LSR_PE)
+                        priv->icount.parity++;
+                if (lsr & UART_LSR_OE)
+                        priv->icount.overrun++;
+        }
+}
+
 static int ssu100_process_packet(struct tty_struct *tty,
                                  struct usb_serial_port *port,
                                  struct ssu100_port_private *priv,
@@ -556,15 +638,9 @@ static int ssu100_process_packet(struct tty_struct *tty,
             (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
             ((packet[2] == 0x00) || (packet[2] == 0x01))) {
                 if (packet[2] == 0x00)
-                        priv->shadowLSR = packet[3] & (UART_LSR_OE |
-                                                       UART_LSR_PE |
-                                                       UART_LSR_FE |
-                                                       UART_LSR_BI);
-
-                if (packet[2] == 0x01) {
-                        priv->shadowMSR = packet[3];
-                        wake_up_interruptible(&priv->delta_msr_wait);
-                }
+                        ssu100_update_lsr(port, packet[3]);
+                if (packet[2] == 0x01)
+                        ssu100_update_msr(port, packet[3]);
 
                 len -= 4;
                 ch = packet + 4;