From 482120084d843d4cbb7ff3eb84510a1471130ce0 Mon Sep 17 00:00:00 2001 From: Thomas Hoehn Date: Sat, 10 Feb 2007 01:46:05 -0800 Subject: [PATCH] Perle multimodem card (PCI-RAS) detection Get the Perle quad-modem PCI card (PCI-RAS4) detected by serial driver. It may also get the PCI-RAS8 running, but can't guarantee as I didn't had one for testing. Signed-off-by: Thomas Hoehn Cc: Russell King Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/serial/8250.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/serial/8250.c') diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 5261f0af8b10..2964ca9df5a0 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -920,12 +920,16 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags) #ifdef __i386__ outb(0xff, 0x080); #endif - scratch2 = serial_inp(up, UART_IER); + /* + * Mask out IER[7:4] bits for test as some UARTs (e.g. TL + * 16C754B) allow only to modify them if an EFR bit is set. + */ + scratch2 = serial_inp(up, UART_IER) & 0x0f; serial_outp(up, UART_IER, 0x0F); #ifdef __i386__ outb(0, 0x080); #endif - scratch3 = serial_inp(up, UART_IER); + scratch3 = serial_inp(up, UART_IER) & 0x0f; serial_outp(up, UART_IER, scratch); if (scratch2 != 0 || scratch3 != 0x0F) { /* -- cgit v1.2.3