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[PATCH] Serial: Convert 8250 revision-based bug fixes to bug bitmask

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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 <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2005-06-23 10:43:04 +01:00
parent b7c84c6ada
commit 4ba5e35daa
2 changed files with 15 additions and 10 deletions
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23
drivers/serial/8250.c
View File

@ -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) {

2
drivers/serial/8250.h
View File

@ -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