The function size_fifo wants to backup the FCR register by reading it, but
it is a write-only register. A read to this adress returns the IIR register.
The size_fifo function is only used during autoconfig, and after autoconfig
the FIFO are cleared and deactivated, so we don't need to save FCR.
Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@xxxxxxxxxxx>
________________________________________________
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diff -Naur linux-2.6.18_bugs/drivers/serial/8250.c linux-2.6.18_fixes/drivers/serial/8250.c
--- linux-2.6.18_bugs/drivers/serial/8250.c 2006-10-06 09:45:26.000000000 +0200
+++ linux-2.6.18_fixes/drivers/serial/8250.c 2006-10-06 09:30:14.000000000 +0200
@@ -539,13 +539,12 @@
*/
static int size_fifo(struct uart_8250_port *up)
{
- unsigned char old_fcr, old_mcr, old_lcr;
+ unsigned char old_mcr, old_lcr;
unsigned short old_dl;
int count;
old_lcr = serial_inp(up, UART_LCR);
serial_outp(up, UART_LCR, 0);
- old_fcr = serial_inp(up, UART_FCR);
old_mcr = serial_inp(up, UART_MCR);
serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
@@ -560,7 +559,6 @@
for (count = 0; (serial_inp(up, UART_LSR) & UART_LSR_DR) &&
(count < 256); count++)
serial_inp(up, UART_RX);
- serial_outp(up, UART_FCR, old_fcr);
serial_outp(up, UART_MCR, old_mcr);
serial_outp(up, UART_LCR, UART_LCR_DLAB);
serial_dl_write(up, old_dl);
