media: sunxi-cir: Remove unnecessary spinlock

Only one register, SUNXI_IR_CIR_REG, is accessed from outside the
interrupt handler, and that register is not accessed from inside it.
As there is no overlap between different contexts, no lock is needed.

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
index 0a7f7eab3cc331cc951aaa694b3f2843a53334a3..48be400421cd909af83fd12b8e62e5403b9261e7 100644 (file)
--- a/drivers/media/rc/sunxi-cir.c
+++ b/drivers/media/rc/sunxi-cir.c
@@ -86,7 +86,6 @@ struct sunxi_ir_quirks {
 };
 
 struct sunxi_ir {
-       spinlock_t      ir_lock;
        struct rc_dev   *rc;
        void __iomem    *base;
        int             irq;
@@ -105,8 +104,6 @@ static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
        struct sunxi_ir *ir = dev_id;
        struct ir_raw_event rawir = {};
 
-       spin_lock(&ir->ir_lock);
-
        status = readl(ir->base + SUNXI_IR_RXSTA_REG);
 
        /* clean all pending statuses */
@@ -137,8 +134,6 @@ static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
                ir_raw_event_handle(ir->rc);
        }
 
-       spin_unlock(&ir->ir_lock);
-
        return IRQ_HANDLED;
 }
 
@@ -160,17 +155,14 @@ static int sunxi_ir_set_timeout(struct rc_dev *rc_dev, unsigned int timeout)
 {
        struct sunxi_ir *ir = rc_dev->priv;
        unsigned int base_clk = clk_get_rate(ir->clk);
-       unsigned long flags;
 
        unsigned int ithr = sunxi_usec_to_ithr(base_clk, timeout);
 
        dev_dbg(rc_dev->dev.parent, "setting idle threshold to %u\n", ithr);
 
-       spin_lock_irqsave(&ir->ir_lock, flags);
        /* Set noise threshold and idle threshold */
        writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE) | REG_CIR_ITHR(ithr),
               ir->base + SUNXI_IR_CIR_REG);
-       spin_unlock_irqrestore(&ir->ir_lock, flags);
 
        rc_dev->timeout = sunxi_ithr_to_usec(base_clk, ithr);
 
@@ -199,8 +191,6 @@ static int sunxi_ir_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
-       spin_lock_init(&ir->ir_lock);
-
        ir->fifo_size = quirks->fifo_size;
 
        /* Clock */