Commit 3398cc4f authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Greg Kroah-Hartman
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serial: 8250: Add IIR FIFOs enabled field properly 



Don't use magic literals & comments but define a real field instead
for UART_IIR_FIFO_ENABLED and name also the values.

Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-5-ilpo.jarvinen@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 67a9aee7

drivers/tty/serial/8250/8250_port.c

+7 −10
Original line number Diff line number Diff line
@@ -1293,22 +1293,19 @@ static void autoconfig(struct uart_8250_port *up) 


	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);



	/* Assign this as it is to truncate any bits above 7.  */

	scratch = serial_in(up, UART_IIR);



	switch (scratch >> 6) {

	case 0:

	switch (serial_in(up, UART_IIR) & UART_IIR_FIFO_ENABLED) {

	case UART_IIR_FIFO_ENABLED_8250:

		autoconfig_8250(up);

		break;

	case 1:

		port->type = PORT_UNKNOWN;

		break;

	case 2:

	case UART_IIR_FIFO_ENABLED_16550:

		port->type = PORT_16550;

		break;

	case 3:

	case UART_IIR_FIFO_ENABLED_16550A:

		autoconfig_16550a(up);

		break;

	default:

		port->type = PORT_UNKNOWN;

		break;

	}



#ifdef CONFIG_SERIAL_8250_RSA

include/uapi/linux/serial_reg.h

+4 −0
Original line number Diff line number Diff line
@@ -44,6 +44,10 @@ 
#define UART_IIR_RX_TIMEOUT	0x0c /* OMAP RX Timeout interrupt */

#define UART_IIR_XOFF		0x10 /* OMAP XOFF/Special Character */

#define UART_IIR_CTS_RTS_DSR	0x20 /* OMAP CTS/RTS/DSR Change */

#define UART_IIR_FIFO_ENABLED	0xc0 /* FIFOs enabled / port type identification */

#define  UART_IIR_FIFO_ENABLED_8250	0x00	/* 8250: no FIFO */

#define  UART_IIR_FIFO_ENABLED_16550	0x80	/* 16550: (broken/unusable) FIFO */

#define  UART_IIR_FIFO_ENABLED_16550A	0xc0	/* 16550A: FIFO enabled */



#define UART_FCR	2	/* Out: FIFO Control Register */

#define UART_FCR_ENABLE_FIFO	0x01 /* Enable the FIFO */