diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/serial/8250.c | 23 | ||||
| -rw-r--r-- | 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 30e8beb71430..27cc288e91d0 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 4f3d62f222f4..cd5c3dd2d910 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 |