mxser: extract port ISR

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@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-14-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 9ba3af4626c6ddefd293b278d0b7ba62740d592a..555b9b37b52f312a0c5bfdaddb09a060a6d9b730 100644 (file)
--- 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);
                }