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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-23 16:58:55 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-23 16:58:55 -0700
commitf46f6b20cb01508f5020142ff91021f8fb39550b (patch)
tree30b8aa2014b03840a5f18d9196639cc80617c8c5 /drivers
parenta8ad86f2dc46356f87be1327dabc18bdbda32f50 (diff)
parent67f7654ea1f11fac1cf4a33bf9a5d9079d122e70 (diff)
Merge master.kernel.org:/home/rmk/linux-2.6-serial
Diffstat (limited to 'drivers')
-rw-r--r--drivers/serial/8250.c54
-rw-r--r--drivers/serial/8250.h3
2 files changed, 47 insertions, 10 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 30e8beb7143..79f67fd863e 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -132,9 +132,9 @@ struct uart_8250_port {
struct uart_port port;
struct timer_list timer; /* "no irq" timer */
struct list_head list; /* ports on this IRQ */
- unsigned int capabilities; /* port capabilities */
+ unsigned short capabilities; /* port capabilities */
+ unsigned short bugs; /* port bugs */
unsigned int tx_loadsz; /* transmit fifo load size */
- unsigned short rev;
unsigned char acr;
unsigned char ier;
unsigned char lcr;
@@ -560,7 +560,14 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
if (id1 == 0x16 && id2 == 0xC9 &&
(id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
up->port.type = PORT_16C950;
- up->rev = rev | (id3 << 8);
+
+ /*
+ * Enable work around for the Oxford Semiconductor 952 rev B
+ * chip which causes it to seriously miscalculate baud rates
+ * when DLL is 0.
+ */
+ if (id3 == 0x52 && rev == 0x01)
+ up->bugs |= UART_BUG_QUOT;
return;
}
@@ -577,8 +584,6 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
id2 = id1 >> 8;
if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
- if (id2 == 0x10)
- up->rev = id1 & 255;
up->port.type = PORT_16850;
return;
}
@@ -809,6 +814,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
// save_flags(flags); cli();
up->capabilities = 0;
+ up->bugs = 0;
if (!(up->port.flags & UPF_BUGGY_UART)) {
/*
@@ -1021,6 +1027,8 @@ static void serial8250_stop_tx(struct uart_port *port, unsigned int tty_stop)
}
}
+static void transmit_chars(struct uart_8250_port *up);
+
static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
@@ -1028,6 +1036,14 @@ static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start)
if (!(up->ier & UART_IER_THRI)) {
up->ier |= UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
+
+ if (up->bugs & UART_BUG_TXEN) {
+ unsigned char lsr, iir;
+ lsr = serial_in(up, UART_LSR);
+ iir = serial_in(up, UART_IIR);
+ if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
+ transmit_chars(up);
+ }
}
/*
* We only do this from uart_start
@@ -1433,6 +1449,7 @@ static int serial8250_startup(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned long flags;
+ unsigned char lsr, iir;
int retval;
up->capabilities = uart_config[up->port.type].flags;
@@ -1536,6 +1553,26 @@ static int serial8250_startup(struct uart_port *port)
up->port.mctrl |= TIOCM_OUT2;
serial8250_set_mctrl(&up->port, up->port.mctrl);
+
+ /*
+ * Do a quick test to see if we receive an
+ * interrupt when we enable the TX irq.
+ */
+ serial_outp(up, UART_IER, UART_IER_THRI);
+ lsr = serial_in(up, UART_LSR);
+ iir = serial_in(up, UART_IIR);
+ serial_outp(up, UART_IER, 0);
+
+ if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
+ if (!(up->bugs & UART_BUG_TXEN)) {
+ up->bugs |= UART_BUG_TXEN;
+ pr_debug("ttyS%d - enabling bad tx status workarounds\n",
+ port->line);
+ }
+ } else {
+ up->bugs &= ~UART_BUG_TXEN;
+ }
+
spin_unlock_irqrestore(&up->port.lock, flags);
/*
@@ -1677,12 +1714,9 @@ serial8250_set_termios(struct uart_port *port, struct termios *termios,
quot = serial8250_get_divisor(port, baud);
/*
- * Work around a bug in the Oxford Semiconductor 952 rev B
- * chip which causes it to seriously miscalculate baud rates
- * when DLL is 0.
+ * Oxford Semi 952 rev B workaround
*/
- if ((quot & 0xff) == 0 && up->port.type == PORT_16C950 &&
- up->rev == 0x5201)
+ if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
quot ++;
if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
diff --git a/drivers/serial/8250.h b/drivers/serial/8250.h
index 4f3d62f222f..9225c82faeb 100644
--- a/drivers/serial/8250.h
+++ b/drivers/serial/8250.h
@@ -51,6 +51,9 @@ struct serial8250_config {
#define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
#define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
+#define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
+#define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
+
#if defined(__i386__) && (defined(CONFIG_M386) || defined(CONFIG_M486))
#define _INLINE_ inline
#else