mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-23 09:09:36 +07:00
bd63acf9e9
fsl8250_handle_irq is now used by the of_serial driver, and that fails
if it is a loadable module:
ERROR: "fsl8250_handle_irq" [drivers/tty/serial/of_serial.ko] undefined!
This exports the symbol to avoid randconfig errors.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: d43b54d269 ("serial: Enable Freescale 16550 workaround on arm")
Cc: Scott Wood <scottwood@freescale.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
64 lines
1.8 KiB
C
64 lines
1.8 KiB
C
#include <linux/serial_reg.h>
|
|
#include <linux/serial_8250.h>
|
|
|
|
#include "8250.h"
|
|
|
|
/*
|
|
* Freescale 16550 UART "driver", Copyright (C) 2011 Paul Gortmaker.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This isn't a full driver; it just provides an alternate IRQ
|
|
* handler to deal with an errata. Everything else is just
|
|
* using the bog standard 8250 support.
|
|
*
|
|
* We follow code flow of serial8250_default_handle_irq() but add
|
|
* a check for a break and insert a dummy read on the Rx for the
|
|
* immediately following IRQ event.
|
|
*
|
|
* We re-use the already existing "bug handling" lsr_saved_flags
|
|
* field to carry the "what we just did" information from the one
|
|
* IRQ event to the next one.
|
|
*/
|
|
|
|
int fsl8250_handle_irq(struct uart_port *port)
|
|
{
|
|
unsigned char lsr, orig_lsr;
|
|
unsigned long flags;
|
|
unsigned int iir;
|
|
struct uart_8250_port *up = up_to_u8250p(port);
|
|
|
|
spin_lock_irqsave(&up->port.lock, flags);
|
|
|
|
iir = port->serial_in(port, UART_IIR);
|
|
if (iir & UART_IIR_NO_INT) {
|
|
spin_unlock_irqrestore(&up->port.lock, flags);
|
|
return 0;
|
|
}
|
|
|
|
/* This is the WAR; if last event was BRK, then read and return */
|
|
if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {
|
|
up->lsr_saved_flags &= ~UART_LSR_BI;
|
|
port->serial_in(port, UART_RX);
|
|
spin_unlock_irqrestore(&up->port.lock, flags);
|
|
return 1;
|
|
}
|
|
|
|
lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);
|
|
|
|
if (lsr & (UART_LSR_DR | UART_LSR_BI))
|
|
lsr = serial8250_rx_chars(up, lsr);
|
|
|
|
serial8250_modem_status(up);
|
|
|
|
if (lsr & UART_LSR_THRE)
|
|
serial8250_tx_chars(up);
|
|
|
|
up->lsr_saved_flags = orig_lsr;
|
|
spin_unlock_irqrestore(&up->port.lock, flags);
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fsl8250_handle_irq);
|