[PATCH 13/70] mxser: extract port ISR

From: Jiri Slaby
Date: Fri Jun 18 2021 - 02:16:22 EST


The ISR is terrible mix of letters. Let's extract the proper per-port
handling to a separate function called mxser_port_isr. This way, we can
actually see what both mxser_interrupt and mxser_port_isr do now.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/tty/mxser.c | 119 ++++++++++++++++++++++++--------------------
1 file changed, 64 insertions(+), 55 deletions(-)

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 9ba3af4626c6..555b9b37b52f 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -2203,18 +2203,78 @@ static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port
}
}

+static bool mxser_port_isr(struct mxser_port *port)
+{
+ struct tty_struct *tty;
+ u8 iir, msr, status;
+ bool error = false;
+
+ iir = inb(port->ioaddr + UART_IIR);
+ if (iir & UART_IIR_NO_INT)
+ return true;
+
+ iir &= MOXA_MUST_IIR_MASK;
+ tty = tty_port_tty_get(&port->port);
+ if (!tty || port->closing || !tty_port_initialized(&port->port)) {
+ status = inb(port->ioaddr + UART_LSR);
+ outb(0x27, port->ioaddr + UART_FCR);
+ inb(port->ioaddr + UART_MSR);
+
+ error = true;
+ goto put_tty;
+ }
+
+ status = inb(port->ioaddr + UART_LSR);
+
+ if (status & UART_LSR_PE)
+ port->err_shadow |= NPPI_NOTIFY_PARITY;
+ if (status & UART_LSR_FE)
+ port->err_shadow |= NPPI_NOTIFY_FRAMING;
+ if (status & UART_LSR_OE)
+ port->err_shadow |= NPPI_NOTIFY_HW_OVERRUN;
+ if (status & UART_LSR_BI)
+ port->err_shadow |= NPPI_NOTIFY_BREAK;
+
+ if (port->board->must_hwid) {
+ if (iir == MOXA_MUST_IIR_GDA ||
+ iir == MOXA_MUST_IIR_RDA ||
+ iir == MOXA_MUST_IIR_RTO ||
+ iir == MOXA_MUST_IIR_LSR)
+ status = mxser_receive_chars(tty, port, status);
+ } else {
+ status &= port->read_status_mask;
+ if (status & UART_LSR_DR)
+ status = mxser_receive_chars(tty, port, status);
+ }
+
+ msr = inb(port->ioaddr + UART_MSR);
+ if (msr & UART_MSR_ANY_DELTA)
+ mxser_check_modem_status(tty, port, msr);
+
+ if (port->board->must_hwid) {
+ if (iir == 0x02 && (status & UART_LSR_THRE))
+ mxser_transmit_chars(tty, port);
+ } else {
+ if (status & UART_LSR_THRE)
+ mxser_transmit_chars(tty, port);
+ }
+
+put_tty:
+ tty_kref_put(tty);
+
+ return error;
+}
+
/*
* This is the serial driver's generic interrupt routine
*/
static irqreturn_t mxser_interrupt(int irq, void *dev_id)
{
- int status, iir, i;
struct mxser_board *brd = dev_id;
struct mxser_port *port;
- int max, irqbits, bits, msr;
unsigned int int_cnt, pass_counter = 0;
+ int max, irqbits, bits, i;
int handled = IRQ_NONE;
- struct tty_struct *tty;

max = brd->info->nports;
while (pass_counter++ < MXSER_ISR_PASS_LIMIT) {
@@ -2233,59 +2293,8 @@ static irqreturn_t mxser_interrupt(int irq, void *dev_id)
int_cnt = 0;
spin_lock(&port->slock);
do {
- iir = inb(port->ioaddr + UART_IIR);
- if (iir & UART_IIR_NO_INT)
- break;
- iir &= MOXA_MUST_IIR_MASK;
- tty = tty_port_tty_get(&port->port);
- if (!tty || port->closing ||
- !tty_port_initialized(&port->port)) {
- status = inb(port->ioaddr + UART_LSR);
- outb(0x27, port->ioaddr + UART_FCR);
- inb(port->ioaddr + UART_MSR);
- tty_kref_put(tty);
+ if (mxser_port_isr(port))
break;
- }
-
- status = inb(port->ioaddr + UART_LSR);
-
- if (status & UART_LSR_PE)
- port->err_shadow |= NPPI_NOTIFY_PARITY;
- if (status & UART_LSR_FE)
- port->err_shadow |= NPPI_NOTIFY_FRAMING;
- if (status & UART_LSR_OE)
- port->err_shadow |=
- NPPI_NOTIFY_HW_OVERRUN;
- if (status & UART_LSR_BI)
- port->err_shadow |= NPPI_NOTIFY_BREAK;
-
- if (port->board->must_hwid) {
- if (iir == MOXA_MUST_IIR_GDA ||
- iir == MOXA_MUST_IIR_RDA ||
- iir == MOXA_MUST_IIR_RTO ||
- iir == MOXA_MUST_IIR_LSR)
- status = mxser_receive_chars(tty,
- port, status);
-
- } else {
- status &= port->read_status_mask;
- if (status & UART_LSR_DR)
- status = mxser_receive_chars(tty,
- port, status);
- }
- msr = inb(port->ioaddr + UART_MSR);
- if (msr & UART_MSR_ANY_DELTA)
- mxser_check_modem_status(tty, port, msr);
-
- if (port->board->must_hwid) {
- if (iir == 0x02 && (status &
- UART_LSR_THRE))
- mxser_transmit_chars(tty, port);
- } else {
- if (status & UART_LSR_THRE)
- mxser_transmit_chars(tty, port);
- }
- tty_kref_put(tty);
} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);
spin_unlock(&port->slock);
}
--
2.32.0