[PATCH] serial: serial_txx9 driver update

Update the serial_txx9 driver.

 * More strict check in verify_port.  Cleanup.
 * Do not insert a char caused previous overrun.
 * Fix some spin_locks.
 * Do not call uart_add_one_port for absent ports.

Also, this patch removes a BROKEN tag from Kconfig.  This driver has been
marked as BROKEN by removal of uart_register_port, but it has been solved
already on Sep 2005.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 42 insertions, 37 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 89e5413cc2a3..c66ef96c71b4 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -866,7 +866,7 @@ config SERIAL_M32R_PLDSIO
 
 config SERIAL_TXX9
         bool "TMPTX39XX/49XX SIO support"
-        depends HAS_TXX9_SERIAL && BROKEN
+        depends HAS_TXX9_SERIAL
         select SERIAL_CORE
         default y
 
diff --git a/drivers/serial/serial_txx9.c b/drivers/serial/serial_txx9.c
index ee98a867bc6d..141173efd463 100644
--- a/drivers/serial/serial_txx9.c
+++ b/drivers/serial/serial_txx9.c
@@ -33,6 +33,10 @@
  *      1.02    Cleanup. (import 8250.c changes)
  *      1.03    Fix low-latency mode. (import 8250.c changes)
  *      1.04    Remove usage of deprecated functions, cleanup.
+ *      1.05    More strict check in verify_port.  Cleanup.
+ *      1.06    Do not insert a char caused previous overrun.
+ *              Fix some spin_locks.
+ *              Do not call uart_add_one_port for absent ports.
  */
 #include <linux/config.h>
 
@@ -57,7 +61,7 @@
 #include <asm/io.h>
 #include <asm/irq.h>
 
-static char *serial_version = "1.04";
+static char *serial_version = "1.06";
 static char *serial_name = "TX39/49 Serial driver";
 
 #define PASS_LIMIT      256
@@ -94,6 +98,8 @@ static char *serial_name = "TX39/49 Serial driver";
 #define UART_NR  4
 #endif
 
+#define HIGH_BITS_OFFSET        ((sizeof(long)-sizeof(int))*8)
+
 struct uart_txx9_port {
         struct uart_port        port;
 
@@ -210,7 +216,7 @@ static inline unsigned int sio_in(struct uart_txx9_port *up, int offset)
 {
         switch (up->port.iotype) {
         default:
-                return *(volatile u32 *)(up->port.membase + offset);
+                return __raw_readl(up->port.membase + offset);
         case UPIO_PORT:
                 return inl(up->port.iobase + offset);
         }
@@ -221,7 +227,7 @@ sio_out(struct uart_txx9_port *up, int offset, int value)
 {
         switch (up->port.iotype) {
         default:
-                *(volatile u32 *)(up->port.membase + offset) = value;
+                __raw_writel(value, up->port.membase + offset);
                 break;
         case UPIO_PORT:
                 outl(value, up->port.iobase + offset);
@@ -259,34 +265,19 @@ sio_quot_set(struct uart_txx9_port *up, int quot)
 static void serial_txx9_stop_tx(struct uart_port *port)
 {
         struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-        unsigned long flags;
-
-        spin_lock_irqsave(&up->port.lock, flags);
         sio_mask(up, TXX9_SIDICR, TXX9_SIDICR_TIE);
-        spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_start_tx(struct uart_port *port)
 {
         struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-        unsigned long flags;
-
-        spin_lock_irqsave(&up->port.lock, flags);
         sio_set(up, TXX9_SIDICR, TXX9_SIDICR_TIE);
-        spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_stop_rx(struct uart_port *port)
 {
         struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-        unsigned long flags;
-
-        spin_lock_irqsave(&up->port.lock, flags);
         up->port.read_status_mask &= ~TXX9_SIDISR_RDIS;
-#if 0
-        sio_mask(up, TXX9_SIDICR, TXX9_SIDICR_RIE);
-#endif
-        spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_enable_ms(struct uart_port *port)
@@ -302,12 +293,16 @@ receive_chars(struct uart_txx9_port *up, unsigned int *status, struct pt_regs *r
         unsigned int disr = *status;
         int max_count = 256;
         char flag;
+        unsigned int next_ignore_status_mask;
 
         do {
                 ch = sio_in(up, TXX9_SIRFIFO);
                 flag = TTY_NORMAL;
                 up->port.icount.rx++;
 
+                /* mask out RFDN_MASK bit added by previous overrun */
+                next_ignore_status_mask =
+                        up->port.ignore_status_mask & ~TXX9_SIDISR_RFDN_MASK;
                 if (unlikely(disr & (TXX9_SIDISR_UBRK | TXX9_SIDISR_UPER |
                                      TXX9_SIDISR_UFER | TXX9_SIDISR_UOER))) {
                         /*
@@ -328,8 +323,17 @@ receive_chars(struct uart_txx9_port *up, unsigned int *status, struct pt_regs *r
                                 up->port.icount.parity++;
                         else if (disr & TXX9_SIDISR_UFER)
                                 up->port.icount.frame++;
-                        if (disr & TXX9_SIDISR_UOER)
+                        if (disr & TXX9_SIDISR_UOER) {
                                 up->port.icount.overrun++;
+                                /*
+                                 * The receiver read buffer still hold
+                                 * a char which caused overrun.
+                                 * Ignore next char by adding RFDN_MASK
+                                 * to ignore_status_mask temporarily.
+                                 */
+                                next_ignore_status_mask |=
+                                        TXX9_SIDISR_RFDN_MASK;
+                        }
 
                         /*
                          * Mask off conditions which should be ingored.
@@ -349,6 +353,7 @@ receive_chars(struct uart_txx9_port *up, unsigned int *status, struct pt_regs *r
                 uart_insert_char(&up->port, disr, TXX9_SIDISR_UOER, ch, flag);
 
         ignore_char:
+                up->port.ignore_status_mask = next_ignore_status_mask;
                 disr = sio_in(up, TXX9_SIDISR);
         } while (!(disr & TXX9_SIDISR_UVALID) && (max_count-- > 0));
         spin_unlock(&up->port.lock);
@@ -450,14 +455,11 @@ static unsigned int serial_txx9_get_mctrl(struct uart_port *port)
 static void serial_txx9_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
         struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-        unsigned long flags;
 
-        spin_lock_irqsave(&up->port.lock, flags);
         if (mctrl & TIOCM_RTS)
                 sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_RTSSC);
         else
                 sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_RTSSC);
-        spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_break_ctl(struct uart_port *port, int break_state)
@@ -784,8 +786,14 @@ static void serial_txx9_config_port(struct uart_port *port, int uflags)
 static int
 serial_txx9_verify_port(struct uart_port *port, struct serial_struct *ser)
 {
-        if (ser->irq < 0 ||
-            ser->baud_base < 9600 || ser->type != PORT_TXX9)
+        unsigned long new_port = ser->port;
+        if (HIGH_BITS_OFFSET)
+                new_port += (unsigned long)ser->port_high << HIGH_BITS_OFFSET;
+        if (ser->type != port->type ||
+            ser->irq != port->irq ||
+            ser->io_type != port->iotype ||
+            new_port != port->iobase ||
+            (unsigned long)ser->iomem_base != port->mapbase)
                 return -EINVAL;
         return 0;
 }
@@ -827,7 +835,8 @@ static void __init serial_txx9_register_ports(struct uart_driver *drv)
 
                 up->port.line = i;
                 up->port.ops = &serial_txx9_pops;
-                uart_add_one_port(drv, &up->port);
+                if (up->port.iobase || up->port.mapbase)
+                        uart_add_one_port(drv, &up->port);
         }
 }
 
@@ -927,11 +936,6 @@ static int serial_txx9_console_setup(struct console *co, char *options)
                 return -ENODEV;
 
         /*
-         * Temporary fix.
-         */
-        spin_lock_init(&port->lock);
-
-        /*
          *      Disable UART interrupts, set DTR and RTS high
          *      and set speed.
          */
@@ -1041,11 +1045,10 @@ static int __devinit serial_txx9_register_port(struct uart_port *port)
         mutex_lock(&serial_txx9_mutex);
         for (i = 0; i < UART_NR; i++) {
                 uart = &serial_txx9_ports[i];
-                if (uart->port.type == PORT_UNKNOWN)
+                if (!(uart->port.iobase || uart->port.mapbase))
                         break;
         }
         if (i < UART_NR) {
-                uart_remove_one_port(&serial_txx9_reg, &uart->port);
                 uart->port.iobase = port->iobase;
                 uart->port.membase = port->membase;
                 uart->port.irq      = port->irq;
@@ -1080,9 +1083,8 @@ static void __devexit serial_txx9_unregister_port(int line)
         uart->port.type = PORT_UNKNOWN;
         uart->port.iobase = 0;
         uart->port.mapbase = 0;
-        uart->port.membase = 0;
+        uart->port.membase = NULL;
         uart->port.dev = NULL;
-        uart_add_one_port(&serial_txx9_reg, &uart->port);
         mutex_unlock(&serial_txx9_mutex);
 }
 
@@ -1198,8 +1200,11 @@ static void __exit serial_txx9_exit(void)
 #ifdef ENABLE_SERIAL_TXX9_PCI
         pci_unregister_driver(&serial_txx9_pci_driver);
 #endif
-        for (i = 0; i < UART_NR; i++)
-                uart_remove_one_port(&serial_txx9_reg, &serial_txx9_ports[i].port);
+        for (i = 0; i < UART_NR; i++) {
+                struct uart_txx9_port *up = &serial_txx9_ports[i];
+                if (up->port.iobase || up->port.mapbase)
+                        uart_remove_one_port(&serial_txx9_reg, &up->port);
+        }
 
         uart_unregister_driver(&serial_txx9_reg);
 }