Current parport_irq_handler behaviour is not correct when IRQ is shared.
LDDv3 on page 279 requires us:

"Be sure to return IRQ_NONE whenever your handler is called and finds
the device is not interrupting."

This is not the case of parport_irq_handler.
Current implementation of IRQ handling use this to optimize shared IRQ processing.
When an action returns IRQ_HANDLED no other actions are processed.

Modify callback function void (*irq_func)(void *) to irqreturn_t (*irq_func)(void *) and return the value in parport_irq_handler

This also fixes https://bugzilla.kernel.org/show_bug.cgi?id=85221

Signed-off-by: Matwey V. Kornilov <redacted>
---
 drivers/char/ppdev.c                       |  4 +++-
 drivers/i2c/busses/i2c-parport.c           |  5 ++++-
 drivers/input/joystick/walkera0701.c       |  6 ++++--
 drivers/net/hamradio/baycom_par.c          |  4 +++-
 drivers/net/plip/plip.c                    |  8 +++++---
 drivers/parport/share.c                    |  6 ++----
 drivers/pps/clients/pps_parport.c          |  6 +++---
 drivers/staging/media/lirc/lirc_parallel.c | 12 +++++++-----
 include/linux/parport.h                    | 12 ++++++++----
 9 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index ae0b42b..61fec51 100644
--- a/drivers/char/ppdev.c
+++ b/drivers/char/ppdev.c

@@ -264,7 +264,7 @@ static ssize_t pp_write (struct file * file, const char __user * buf,
        return bytes_written;
 }

-static void pp_irq (void *private)
+static irqreturn_t pp_irq (void *private)
 {
        struct pp_struct *pp = private;

@@ -275,6 +275,8 @@ static void pp_irq (void *private)

        atomic_inc (&pp->irqc);
        wake_up_interruptible (&pp->irq_wait);
+
+       return IRQ_HANDLED;
 }

 static int register_device (int minor, struct pp_struct *pp)

diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
index a27aae2..7549e10 100644
--- a/drivers/i2c/busses/i2c-parport.c
+++ b/drivers/i2c/busses/i2c-parport.c

@@ -151,7 +151,7 @@ static const struct i2c_algo_bit_data parport_algo_data = {

 /* ----- I2c and parallel port call-back functions and structures --------- */

-static void i2c_parport_irq(void *data)
+static irqreturn_t i2c_parport_irq(void *data)
 {
        struct i2c_par *adapter = data;
        struct i2c_client *ara = adapter->ara;

@@ -159,9 +159,12 @@ static void i2c_parport_irq(void *data)
        if (ara) {
                dev_dbg(&ara->dev, "SMBus alert received\n");
                i2c_handle_smbus_alert(ara);
+               return IRQ_HANDLED;
        } else
                dev_dbg(&adapter->adapter.dev,
                        "SMBus alert received but no ARA client!\n");
+
+       return IRQ_NONE;
 }

 static void i2c_parport_attach(struct parport *port)

diff --git a/drivers/input/joystick/walkera0701.c b/drivers/input/joystick/walkera0701.c
index b76ac58..f3903a6 100644
--- a/drivers/input/joystick/walkera0701.c
+++ b/drivers/input/joystick/walkera0701.c

@@ -124,7 +124,7 @@ static inline int read_ack(struct pardevice *p)
 }

 /* falling edge, prepare to BIN value calculation */
-static void walkera0701_irq_handler(void *handler_data)
+static irqreturn_t walkera0701_irq_handler(void *handler_data)
 {
        u64 pulse_time;
        struct walkera_dev *w = handler_data;

@@ -136,7 +136,7 @@ static void walkera0701_irq_handler(void *handler_data)
        /* cancel timer, if in handler or active do resync */
        if (unlikely(0 != hrtimer_try_to_cancel(&w->timer))) {
                w->counter = NO_SYNC;
-               return;
+               return IRQ_HANDLED;
        }

        if (w->counter < NO_SYNC) {

@@ -166,6 +166,8 @@ static void walkera0701_irq_handler(void *handler_data)
                w->counter = 0;

        hrtimer_start(&w->timer, ktime_set(0, BIN_SAMPLE), HRTIMER_MODE_REL);
+
+       return IRQ_HANDLED;
 }

 static enum hrtimer_restart timer_handler(struct hrtimer

diff --git a/drivers/net/hamradio/baycom_par.c b/drivers/net/hamradio/baycom_par.c
index acb6369..1fd9a7b 100644
--- a/drivers/net/hamradio/baycom_par.c
+++ b/drivers/net/hamradio/baycom_par.c

@@ -269,7 +269,7 @@ static __inline__ void par96_rx(struct net_device *dev, struct baycom_state *bc)

 /* --------------------------------------------------------------------- */

-static void par96_interrupt(void *dev_id)
+static irqreturn_t par96_interrupt(void *dev_id)
 {
        struct net_device *dev = dev_id;
        struct baycom_state *bc = netdev_priv(dev);

@@ -292,6 +292,8 @@ static void par96_interrupt(void *dev_id)
        hdlcdrv_transmitter(dev, &bc->hdrv);
        hdlcdrv_receiver(dev, &bc->hdrv);
         local_irq_disable();
+
+       return IRQ_HANDLED;
 }

 /* --------------------------------------------------------------------- */

diff --git a/drivers/net/plip/plip.c b/drivers/net/plip/plip.c
index 040b897..00a8b3a 100644
--- a/drivers/net/plip/plip.c
+++ b/drivers/net/plip/plip.c

@@ -143,7 +143,7 @@ static void plip_bh(struct work_struct *work);
 static void plip_timer_bh(struct work_struct *work);

 /* Interrupt handler */
-static void plip_interrupt(void *dev_id);
+static irqreturn_t plip_interrupt(void *dev_id);

 /* Functions for DEV methods */
 static int plip_tx_packet(struct sk_buff *skb, struct net_device *dev);

@@ -900,7 +900,7 @@ plip_error(struct net_device *dev, struct net_local *nl,
 }

 /* Handle the parallel port interrupts. */
-static void
+static irqreturn_t
 plip_interrupt(void *dev_id)
 {
        struct net_device *dev = dev_id;

@@ -919,7 +919,7 @@ plip_interrupt(void *dev_id)
                if ((dev->irq != -1) && (net_debug > 1))
                        printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
                spin_unlock_irqrestore (&nl->lock, flags);
-               return;
+               return IRQ_NONE;
        }

        if (net_debug > 3)

@@ -948,6 +948,8 @@ plip_interrupt(void *dev_id)
        }

        spin_unlock_irqrestore(&nl->lock, flags);
+
+       return IRQ_HANDLED;
 }

 static int

diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index 3fa6624..1fd8dc2 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c

@@ -523,7 +523,7 @@ void parport_remove_port(struct parport *port)
 struct pardevice *
 parport_register_device(struct parport *port, const char *name,
                        int (*pf)(void *), void (*kf)(void *),
-                       void (*irq_func)(void *),
+                       irqreturn_t (*irq_func)(void *),
                        int flags, void *handle)
 {
        struct pardevice *tmp;

@@ -1006,9 +1006,7 @@ irqreturn_t parport_irq_handler(int irq, void *dev_id)
 {
        struct parport *port = dev_id;

-       parport_generic_irq(port);
-
-       return IRQ_HANDLED;
+       return parport_generic_irq(port);
 }

 /* Exported symbols for modules. */

diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c
index 38a8bbe..9acf376 100644
--- a/drivers/pps/clients/pps_parport.c
+++ b/drivers/pps/clients/pps_parport.c

@@ -64,7 +64,7 @@ static inline int signal_is_set(struct parport *port)
 }

 /* parport interrupt handler */
-static void parport_irq(void *handle)
+static irqreturn_t parport_irq(void *handle)
 {
        struct pps_event_time ts_assert, ts_clear;
        struct pps_client_pp *dev = handle;

@@ -122,7 +122,7 @@ out_assert:
        /* fire assert event */
        pps_event(dev->pps, &ts_assert,
                        PPS_CAPTUREASSERT, NULL);
-       return;
+       return IRQ_HANDLED;

 out_both:
        /* fire assert event */

@@ -131,7 +131,7 @@ out_both:
        /* fire clear event */
        pps_event(dev->pps, &ts_clear,
                        PPS_CAPTURECLEAR, NULL);
-       return;
+       return IRQ_HANDLED;
 }

 static void parport_attach(struct parport *port)

diff --git a/drivers/staging/media/lirc/lirc_parallel.c b/drivers/staging/media/lirc/lirc_parallel.c
index 672858a..63fdc27 100644
--- a/drivers/staging/media/lirc/lirc_parallel.c
+++ b/drivers/staging/media/lirc/lirc_parallel.c

@@ -219,7 +219,7 @@ static void rbuf_write(int signal)
        wptr = nwptr;
 }

-static void lirc_lirc_irq_handler(void *blah)
+static irqreturn_t lirc_lirc_irq_handler(void *blah)
 {
        struct timeval tv;
        static struct timeval lasttv;

@@ -230,10 +230,10 @@ static void lirc_lirc_irq_handler(void *blah)
        unsigned int timeout;

        if (!is_open)
-               return;
+               return IRQ_NONE;

        if (!is_claimed)
-               return;
+               return IRQ_NONE;

 #if 0
        /* disable interrupt */

@@ -241,7 +241,7 @@ static void lirc_lirc_irq_handler(void *blah)
          out(LIRC_PORT_IRQ, in(LIRC_PORT_IRQ) & (~LP_PINTEN));
 #endif
        if (check_pselecd && (in(1) & LP_PSELECD))
-               return;
+               return IRQ_NONE;

 #ifdef LIRC_TIMER
        if (init) {

@@ -265,7 +265,7 @@ static void lirc_lirc_irq_handler(void *blah)
                         */
                        timer = init_lirc_timer();
                        /* enable_irq(irq); */
-                       return;
+                       return IRQ_HANDLED;
                }
                init = 1;
        }

@@ -314,6 +314,8 @@ static void lirc_lirc_irq_handler(void *blah)
          enable_irq(irq);
          out(LIRC_PORT_IRQ, in(LIRC_PORT_IRQ)|LP_PINTEN);
        */
+
+       return IRQ_HANDLED;
 }

 /*** file operations ***/

diff --git a/include/linux/parport.h b/include/linux/parport.h
index c22f125..2ab774c 100644
--- a/include/linux/parport.h
+++ b/include/linux/parport.h

@@ -141,7 +141,7 @@ struct pardevice {
        int (*preempt)(void *);
        void (*wakeup)(void *);
        void *private;
-       void (*irq_func)(void *);
+       irqreturn_t (*irq_func)(void *);
        unsigned int flags;
        struct pardevice *next;
        struct pardevice *prev;

@@ -298,7 +298,7 @@ extern void parport_put_port (struct parport *);
 struct pardevice *parport_register_device(struct parport *port,
                          const char *name,
                          int (*pf)(void *), void (*kf)(void *),
-                         void (*irq_func)(void *),
+                         irqreturn_t (*irq_func)(void *),
                          int flags, void *handle);

 /* parport_unregister unlinks a device from the chain. */

@@ -429,13 +429,17 @@ extern void parport_daisy_deselect_all (struct parport *port);
 extern int parport_daisy_select (struct parport *port, int daisy, int mode);

 /* Lowlevel drivers _can_ call this support function to handle irqs.  */
-static inline void parport_generic_irq(struct parport *port)
+static inline irqreturn_t parport_generic_irq(struct parport *port)
 {
+       irqreturn_t ret = IRQ_NONE;
+
        parport_ieee1284_interrupt (port);
        read_lock(&port->cad_lock);
        if (port->cad && port->cad->irq_func)
-               port->cad->irq_func(port->cad->private);
+               ret = port->cad->irq_func(port->cad->private);
        read_unlock(&port->cad_lock);
+
+       return ret;
 }

 /* Prototypes from parport_procfs */
--

2.1.0