[PATCH] spi: hisi-sfc-v3xx: Return IRQ_NONE if no interrupts were detected

[Devyn Liu <liudingyuan@xxxxxxxxxx>]

Return IRQ_NONE from the interrupt handler when no interrupt was
detected. Because an empty interrupt will cause a null pointer error:

    Unable to handle kernel NULL pointer dereference at virtual
  address 0000000000000008
    Call trace:
        complete+0x54/0x100
        hisi_sfc_v3xx_isr+0x2c/0x40 [spi_hisi_sfc_v3xx]
        __handle_irq_event_percpu+0x64/0x1e0
        handle_irq_event+0x7c/0x1cc

Signed-off-by: Devyn Liu <liudingyuan@xxxxxxxxxx>
---
 drivers/spi/spi-hisi-sfc-v3xx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/spi/spi-hisi-sfc-v3xx.c b/drivers/spi/spi-hisi-sfc-v3xx.c
index 9d22018f7985..1301d14483d4 100644
--- a/drivers/spi/spi-hisi-sfc-v3xx.c
+++ b/drivers/spi/spi-hisi-sfc-v3xx.c
@@ -377,6 +377,11 @@ static const struct spi_controller_mem_ops hisi_sfc_v3xx_mem_ops = {
 static irqreturn_t hisi_sfc_v3xx_isr(int irq, void *data)
 {
 	struct hisi_sfc_v3xx_host *host = data;
+	u32 reg;
+
+	reg = readl(host->regbase + HISI_SFC_V3XX_INT_STAT);
+	if (!reg)
+		return IRQ_NONE;
 
 	hisi_sfc_v3xx_disable_int(host);
 
-- 
2.30.0