From 4ba5e35daa90871fcb9b01f5ad1e5723343cc0a9 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 23 Jun 2005 10:43:04 +0100 Subject: [PATCH] Serial: Convert 8250 revision-based bug fixes to bug bitmask For some 8250 port types, we used to check the type of the port, and then determine whether the chip revision means the device is buggy. Instead, introduce a bit array, and set the appropriate bit(s) when we discover a buggy device. Signed-off-by: Russell King --- drivers/serial/8250.c | 23 +++++++++++++---------- drivers/serial/8250.h | 2 ++ 2 files changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 30e8beb7143..27cc288e91d 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)) { /* @@ -1677,12 +1683,9 @@ 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..cd5c3dd2d91 100644 --- a/drivers/serial/8250.h +++ b/drivers/serial/8250.h @@ -51,6 +51,8 @@ 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 */ + #if defined(__i386__) && (defined(CONFIG_M386) || defined(CONFIG_M486)) #define _INLINE_ inline #else -- cgit v1.2.3 From 55d3b282b90620e02e825304a9433732a84c58a5 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 23 Jun 2005 15:05:41 +0100 Subject: [PATCH] Serial: Mobility's 16550A ports need a helping hand The Mobility 16550A serial ports don't behave the same as standard 16550A ports, and need a helping hand to get them going once the transmitter has drained and been disabled. Signed-off-by: Russell King --- drivers/serial/8250.c | 31 +++++++++++++++++++++++++++++++ drivers/serial/8250.h | 1 + 2 files changed, 32 insertions(+) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 27cc288e91d..341c644591a 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1027,6 +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; @@ -1034,6 +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->capabilities & 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 @@ -1439,6 +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; @@ -1542,6 +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->capabilities & UART_BUG_TXEN)) { + up->capabilities |= UART_BUG_TXEN; + pr_debug("ttyS%d - enabling bad tx status workarounds\n", + port->line); + } + } else { + up->capabilities &= ~UART_BUG_TXEN; + } + spin_unlock_irqrestore(&up->port.lock, flags); /* diff --git a/drivers/serial/8250.h b/drivers/serial/8250.h index cd5c3dd2d91..9225c82faeb 100644 --- a/drivers/serial/8250.h +++ b/drivers/serial/8250.h @@ -52,6 +52,7 @@ struct serial8250_config { #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 -- cgit v1.2.3 From 67f7654ea1f11fac1cf4a33bf9a5d9079d122e70 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 23 Jun 2005 22:26:43 +0100 Subject: [PATCH] Serial: Bugs are not capabilities Signed-off-by: Russell King --- drivers/serial/8250.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 341c644591a..79f67fd863e 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1037,7 +1037,7 @@ static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start) up->ier |= UART_IER_THRI; serial_out(up, UART_IER, up->ier); - if (up->capabilities & UART_BUG_TXEN) { + if (up->bugs & UART_BUG_TXEN) { unsigned char lsr, iir; lsr = serial_in(up, UART_LSR); iir = serial_in(up, UART_IIR); @@ -1564,13 +1564,13 @@ static int serial8250_startup(struct uart_port *port) serial_outp(up, UART_IER, 0); if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) { - if (!(up->capabilities & UART_BUG_TXEN)) { - up->capabilities |= UART_BUG_TXEN; + 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->capabilities &= ~UART_BUG_TXEN; + up->bugs &= ~UART_BUG_TXEN; } spin_unlock_irqrestore(&up->port.lock, flags); -- cgit v1.2.3