sw:drv: handle spurous ALIx interrupts

When the FPGA is not programmed it could happen that some ALIx interrupt get asserted due to noise. To avoid to scare users, we hide those errors when the FPGA is not configured. Signed-off-by: Federico Vaga <federico.vaga@cern.ch>

sw:drv: handle spurous ALIx interrupts
When the FPGA is not programmed it could happen that some ALIx interrupt get asserted due to noise. To avoid to scare users, we hide those errors when the FPGA is not configured. Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
77c6d7bf · Federico Vaga · 30cac07e · 77c6d7bf
Commit 77c6d7bf authored Jun 01, 2021 by Federico Vaga
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Showing with 18 additions and 3 deletions

gn412x-gpio.c software/kernel/gn412x-gpio.c +18 -3

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--- a/software/kernel/gn412x-gpio.c
+++ b/software/kernel/gn412x-gpio.c
@@ -470,6 +470,14 @@ out_enable_irq:
 	return ret;
 }

+static bool gn412x_gpio_fpga_is_programmed(struct gn412x_gpio_dev *gn412x)
+{
+	bool done;
+
+	done = gn412x_ioread32(gn412x, FCL_STATUS) & FCL_SPRI_DONE;
+
+	return done;
+}

 static irqreturn_t gn412x_gpio_irq_handler_h(int irq, void *arg)
 {
@@ -484,10 +492,17 @@ static irqreturn_t gn412x_gpio_irq_handler_h(int irq, void *arg)
 	if (unlikely(int_stat & GNINT_STAT_SW_ALL)) /* only for testing */
 		return spec_irq_sw_handler(irq, gn412x);

-	if (WARN(int_stat & GNINT_STAT_ERR_ALL, "GN412x ERROR 0x%08x",
-		 int_stat)) {
+	if (unlikely(int_stat & GNINT_STAT_ERR_ALL)) {
 		gn412x_iowrite32(gn412x, int_stat & GNINT_STAT_ERR_ALL,
-				 GNINT_STAT);
+						 GNINT_STAT);
+		if (!gn412x_gpio_fpga_is_programmed(gn412x))
+			return IRQ_NONE;  /* spurious interrupt if FPGA is not programmed */
+#if KERNEL_VERSION(4, 5, 0) > LINUX_VERSION_CODE
+		dev_err(gn412x->gpiochip.dev, "Local bus error 0x%08x\n", int_stat);
+#else
+		dev_err(gn412x->gpiochip.parent, "Local bus error 0x%08x\n", int_stat);
+#endif
+
 		return IRQ_HANDLED;
 	}