mxser: cleanup LSR handling in mxser_receive_chars
mxser_interrupt is a bit confusing as it passes a pointer to LSR
variable ("status") to mxser_receive_chars. That function can indeed
update the LCR variable. Make this clear by not passing a variable by
reference, instead, return updated status. And change its type
accordingly -- to u8.
Note that the next patches will rework ISR so that even the definition
of status will be u8 soon too.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 6602b27..9ba3af4 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -2056,8 +2056,8 @@ static int mxser_rs_break(struct tty_struct *tty, int break_state)
return 0;
}
-static void mxser_receive_chars(struct tty_struct *tty,
- struct mxser_port *port, int *status)
+static u8 mxser_receive_chars(struct tty_struct *tty,
+ struct mxser_port *port, u8 status)
{
unsigned char ch, gdl;
int ignored = 0;
@@ -2070,12 +2070,12 @@ static void mxser_receive_chars(struct tty_struct *tty,
mxser_stoprx(tty);
if (port->board->must_hwid != MOXA_OTHER_UART) {
- if (*status & UART_LSR_SPECIAL)
+ if (status & UART_LSR_SPECIAL)
goto intr_old;
if (port->board->must_hwid == MOXA_MUST_MU860_HWID &&
- (*status & MOXA_MUST_LSR_RERR))
+ (status & MOXA_MUST_LSR_RERR))
goto intr_old;
- if (*status & MOXA_MUST_LSR_RERR)
+ if (status & MOXA_MUST_LSR_RERR)
goto intr_old;
gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
@@ -2100,28 +2100,28 @@ static void mxser_receive_chars(struct tty_struct *tty,
break;
ch = inb(port->ioaddr + UART_RX);
- if (port->board->must_hwid && (*status & UART_LSR_OE))
+ if (port->board->must_hwid && (status & UART_LSR_OE))
outb(0x23, port->ioaddr + UART_FCR);
- *status &= port->read_status_mask;
- if (*status & port->ignore_status_mask) {
+ status &= port->read_status_mask;
+ if (status & port->ignore_status_mask) {
if (++ignored > 100)
break;
} else {
char flag = 0;
- if (*status & UART_LSR_SPECIAL) {
- if (*status & UART_LSR_BI) {
+ if (status & UART_LSR_SPECIAL) {
+ if (status & UART_LSR_BI) {
flag = TTY_BREAK;
port->icount.brk++;
if (port->port.flags & ASYNC_SAK)
do_SAK(tty);
- } else if (*status & UART_LSR_PE) {
+ } else if (status & UART_LSR_PE) {
flag = TTY_PARITY;
port->icount.parity++;
- } else if (*status & UART_LSR_FE) {
+ } else if (status & UART_LSR_FE) {
flag = TTY_FRAME;
port->icount.frame++;
- } else if (*status & UART_LSR_OE) {
+ } else if (status & UART_LSR_OE) {
flag = TTY_OVERRUN;
port->icount.overrun++;
} else
@@ -2140,8 +2140,8 @@ static void mxser_receive_chars(struct tty_struct *tty,
if (port->board->must_hwid)
break;
- *status = inb(port->ioaddr + UART_LSR);
- } while (*status & UART_LSR_DR);
+ status = inb(port->ioaddr + UART_LSR);
+ } while (status & UART_LSR_DR);
end_intr:
mxvar_log.rxcnt[tty->index] += cnt;
@@ -2149,6 +2149,8 @@ static void mxser_receive_chars(struct tty_struct *tty,
port->mon_data.up_rxcnt += cnt;
tty_flip_buffer_push(&port->port);
+
+ return status;
}
static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port)
@@ -2262,14 +2264,14 @@ static irqreturn_t mxser_interrupt(int irq, void *dev_id)
iir == MOXA_MUST_IIR_RDA ||
iir == MOXA_MUST_IIR_RTO ||
iir == MOXA_MUST_IIR_LSR)
- mxser_receive_chars(tty, port,
- &status);
+ status = mxser_receive_chars(tty,
+ port, status);
} else {
status &= port->read_status_mask;
if (status & UART_LSR_DR)
- mxser_receive_chars(tty, port,
- &status);
+ status = mxser_receive_chars(tty,
+ port, status);
}
msr = inb(port->ioaddr + UART_MSR);
if (msr & UART_MSR_ANY_DELTA)