[v7,02/12] irqchip: loongson-liointc: Workaround LPC IRQ Errata
diff mbox series

Message ID 20200325022916.106641-4-jiaxun.yang@flygoat.com
State Not Applicable
Delegated to: David Miller
Headers show
Series
  • [v7,01/12] irqchip: Add driver for Loongson I/O Local Interrupt Controller
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Commit Message

Jiaxun Yang March 25, 2020, 2:28 a.m. UTC
The 1.0 version of that controller has a bug that status bit
of LPC IRQ sometimes doesn't get set correctly.

So we can always blame LPC IRQ when spurious interrupt happens
at the parent interrupt line which LPC IRQ supposed to route
to.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Co-developed-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-loongson-liointc.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

Patch
diff mbox series

diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c
index 18de2c09ece4..7d2339e638db 100644
--- a/drivers/irqchip/irq-loongson-liointc.c
+++ b/drivers/irqchip/irq-loongson-liointc.c
@@ -32,6 +32,8 @@ 
 
 #define LIOINTC_SHIFT_INTx	4
 
+#define LIOINTC_ERRATA_IRQ	10
+
 struct liointc_handler_data {
 	struct liointc_priv	*priv;
 	u32			parent_int_map;
@@ -41,6 +43,7 @@  struct liointc_priv {
 	struct irq_chip_generic		*gc;
 	struct liointc_handler_data	handler[LIOINTC_NUM_PARENT];
 	u8				map_cache[LIOINTC_CHIP_IRQ];
+	bool				have_lpc_irq_errata;
 };
 
 static void liointc_chained_handle_irq(struct irq_desc *desc)
@@ -54,8 +57,15 @@  static void liointc_chained_handle_irq(struct irq_desc *desc)
 
 	pending = readl(gc->reg_base + LIOINTC_REG_INTC_STATUS);
 
-	if (!pending)
-		spurious_interrupt();
+	if (!pending) {
+		/* Always blame LPC IRQ if we have that bug */
+		if (handler->priv->have_lpc_irq_errata &&
+			(handler->parent_int_map & ~gc->mask_cache &
+			BIT(LIOINTC_ERRATA_IRQ)))
+			pending = BIT(LIOINTC_ERRATA_IRQ);
+		else
+			spurious_interrupt();
+	}
 
 	while (pending) {
 		int bit = __ffs(pending);