[media] media: rc: nuvoton-cir: improve locking in both interrupt handlers

Extend the locking to protect more critical actions like register accesses
in the interrupt handlers.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
index 291d870..d428b4e 100644 (file)
--- a/drivers/media/rc/nuvoton-cir.c
+++ b/drivers/media/rc/nuvoton-cir.c
@@ -727,7 +727,6 @@ static void nvt_handle_rx_fifo_overrun(struct nvt_dev *nvt)
 /* copy data from hardware rx fifo into driver buffer */
 static void nvt_get_rx_ir_data(struct nvt_dev *nvt)
 {
-       unsigned long flags;
        u8 fifocount, val;
        unsigned int b_idx;
        bool overrun = false;
@@ -746,8 +745,6 @@ static void nvt_get_rx_ir_data(struct nvt_dev *nvt)
 
        nvt_dbg("attempting to fetch %u bytes from hw rx fifo", fifocount);
 
-       spin_lock_irqsave(&nvt->nvt_lock, flags);
-
        b_idx = nvt->pkts;
 
        /* This should never happen, but lets check anyway... */
@@ -769,8 +766,6 @@ static void nvt_get_rx_ir_data(struct nvt_dev *nvt)
 
        if (overrun)
                nvt_handle_rx_fifo_overrun(nvt);
-
-       spin_unlock_irqrestore(&nvt->nvt_lock, flags);
 }
 
 static void nvt_cir_log_irqs(u8 status, u8 iren)
@@ -811,6 +806,8 @@ static irqreturn_t nvt_cir_isr(int irq, void *data)
 
        nvt_dbg_verbose("%s firing", __func__);
 
+       spin_lock_irqsave(&nvt->nvt_lock, flags);
+
        /*
         * Get IR Status register contents. Write 1 to ack/clear
         *
@@ -831,6 +828,7 @@ static irqreturn_t nvt_cir_isr(int irq, void *data)
         * status bit whether the related interrupt source is enabled
         */
        if (!(status & iren)) {
+               spin_unlock_irqrestore(&nvt->nvt_lock, flags);
                nvt_dbg_verbose("%s exiting, IRSTS 0x0", __func__);
                return IRQ_NONE;
        }
@@ -852,16 +850,14 @@ static irqreturn_t nvt_cir_isr(int irq, void *data)
                if (nvt_cir_tx_inactive(nvt))
                        nvt_get_rx_ir_data(nvt);
 
-               spin_lock_irqsave(&nvt->nvt_lock, flags);
-
                cur_state = nvt->study_state;
 
-               spin_unlock_irqrestore(&nvt->nvt_lock, flags);
-
                if (cur_state == ST_STUDY_NONE)
                        nvt_clear_cir_fifo(nvt);
        }
 
+       spin_unlock_irqrestore(&nvt->nvt_lock, flags);
+
        if (status & CIR_IRSTS_TE)
                nvt_clear_tx_fifo(nvt);
 
@@ -910,14 +906,18 @@ static irqreturn_t nvt_cir_wake_isr(int irq, void *data)
 
        nvt_dbg_wake("%s firing", __func__);
 
+       spin_lock_irqsave(&nvt->nvt_lock, flags);
+
        status = nvt_cir_wake_reg_read(nvt, CIR_WAKE_IRSTS);
        iren = nvt_cir_wake_reg_read(nvt, CIR_WAKE_IREN);
 
        /* IRQ may be shared with CIR, therefore check for each
         * status bit whether the related interrupt source is enabled
         */
-       if (!(status & iren))
+       if (!(status & iren)) {
+               spin_unlock_irqrestore(&nvt->nvt_lock, flags);
                return IRQ_NONE;
+       }
 
        if (status & CIR_WAKE_IRSTS_IR_PENDING)
                nvt_clear_cir_wake_fifo(nvt);
@@ -933,11 +933,11 @@ static irqreturn_t nvt_cir_wake_isr(int irq, void *data)
                }
 
                nvt_cir_wake_reg_write(nvt, 0, CIR_WAKE_IREN);
-               spin_lock_irqsave(&nvt->nvt_lock, flags);
                nvt->wake_state = ST_WAKE_FINISH;
-               spin_unlock_irqrestore(&nvt->nvt_lock, flags);
        }
 
+       spin_unlock_irqrestore(&nvt->nvt_lock, flags);
+
        nvt_dbg_wake("%s done", __func__);
        return IRQ_HANDLED;
 }