MIPS: ath79: rework IP2/IP3 interrupt handling
The current implementation assumes that flushing the
DDR writeback buffer is required for IP2/IP3 interrupts,
however this is not true for all SoCs.
Use SoC specific IP2/IP3 handlers instead of flushing
the buffers in the dispatcher code.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Acked-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Cc: linux-mips@linux-mips.org
Cc: mcgrof@infradead.org
Patchwork: https://patchwork.linux-mips.org/patch/3509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ath79/irq.c b/arch/mips/ath79/irq.c
index 1b073de..9f87ade 100644
--- a/arch/mips/ath79/irq.c
+++ b/arch/mips/ath79/irq.c
@@ -1,7 +1,7 @@
/*
* Atheros AR71xx/AR724x/AR913x specific interrupt handling
*
- * Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
*
* Parts of this file are based on Atheros' 2.6.15 BSP
@@ -23,8 +23,8 @@
#include <asm/mach-ath79/ar71xx_regs.h>
#include "common.h"
-static unsigned int ath79_ip2_flush_reg;
-static unsigned int ath79_ip3_flush_reg;
+static void (*ath79_ip2_handler)(void);
+static void (*ath79_ip3_handler)(void);
static void ath79_misc_irq_handler(unsigned int irq, struct irq_desc *desc)
{
@@ -152,10 +152,8 @@
if (pending & STATUSF_IP7)
do_IRQ(ATH79_CPU_IRQ_TIMER);
- else if (pending & STATUSF_IP2) {
- ath79_ddr_wb_flush(ath79_ip2_flush_reg);
- do_IRQ(ATH79_CPU_IRQ_IP2);
- }
+ else if (pending & STATUSF_IP2)
+ ath79_ip2_handler();
else if (pending & STATUSF_IP4)
do_IRQ(ATH79_CPU_IRQ_GE0);
@@ -163,10 +161,8 @@
else if (pending & STATUSF_IP5)
do_IRQ(ATH79_CPU_IRQ_GE1);
- else if (pending & STATUSF_IP3) {
- ath79_ddr_wb_flush(ath79_ip3_flush_reg);
- do_IRQ(ATH79_CPU_IRQ_USB);
- }
+ else if (pending & STATUSF_IP3)
+ ath79_ip3_handler();
else if (pending & STATUSF_IP6)
do_IRQ(ATH79_CPU_IRQ_MISC);
@@ -175,22 +171,78 @@
spurious_interrupt();
}
+/*
+ * The IP2/IP3 lines are tied to a PCI/WMAC/USB device. Drivers for
+ * these devices typically allocate coherent DMA memory, however the
+ * DMA controller may still have some unsynchronized data in the FIFO.
+ * Issue a flush in the handlers to ensure that the driver sees
+ * the update.
+ */
+static void ar71xx_ip2_handler(void)
+{
+ ath79_ddr_wb_flush(AR71XX_DDR_REG_FLUSH_PCI);
+ do_IRQ(ATH79_CPU_IRQ_IP2);
+}
+
+static void ar724x_ip2_handler(void)
+{
+ ath79_ddr_wb_flush(AR724X_DDR_REG_FLUSH_PCIE);
+ do_IRQ(ATH79_CPU_IRQ_IP2);
+}
+
+static void ar913x_ip2_handler(void)
+{
+ ath79_ddr_wb_flush(AR913X_DDR_REG_FLUSH_WMAC);
+ do_IRQ(ATH79_CPU_IRQ_IP2);
+}
+
+static void ar933x_ip2_handler(void)
+{
+ ath79_ddr_wb_flush(AR933X_DDR_REG_FLUSH_WMAC);
+ do_IRQ(ATH79_CPU_IRQ_IP2);
+}
+
+static void ar71xx_ip3_handler(void)
+{
+ ath79_ddr_wb_flush(AR71XX_DDR_REG_FLUSH_USB);
+ do_IRQ(ATH79_CPU_IRQ_USB);
+}
+
+static void ar724x_ip3_handler(void)
+{
+ ath79_ddr_wb_flush(AR724X_DDR_REG_FLUSH_USB);
+ do_IRQ(ATH79_CPU_IRQ_USB);
+}
+
+static void ar913x_ip3_handler(void)
+{
+ ath79_ddr_wb_flush(AR913X_DDR_REG_FLUSH_USB);
+ do_IRQ(ATH79_CPU_IRQ_USB);
+}
+
+static void ar933x_ip3_handler(void)
+{
+ ath79_ddr_wb_flush(AR933X_DDR_REG_FLUSH_USB);
+ do_IRQ(ATH79_CPU_IRQ_USB);
+}
+
void __init arch_init_irq(void)
{
if (soc_is_ar71xx()) {
- ath79_ip2_flush_reg = AR71XX_DDR_REG_FLUSH_PCI;
- ath79_ip3_flush_reg = AR71XX_DDR_REG_FLUSH_USB;
+ ath79_ip2_handler = ar71xx_ip2_handler;
+ ath79_ip3_handler = ar71xx_ip3_handler;
} else if (soc_is_ar724x()) {
- ath79_ip2_flush_reg = AR724X_DDR_REG_FLUSH_PCIE;
- ath79_ip3_flush_reg = AR724X_DDR_REG_FLUSH_USB;
+ ath79_ip2_handler = ar724x_ip2_handler;
+ ath79_ip3_handler = ar724x_ip3_handler;
} else if (soc_is_ar913x()) {
- ath79_ip2_flush_reg = AR913X_DDR_REG_FLUSH_WMAC;
- ath79_ip3_flush_reg = AR913X_DDR_REG_FLUSH_USB;
+ ath79_ip2_handler = ar913x_ip2_handler;
+ ath79_ip3_handler = ar913x_ip3_handler;
} else if (soc_is_ar933x()) {
- ath79_ip2_flush_reg = AR933X_DDR_REG_FLUSH_WMAC;
- ath79_ip3_flush_reg = AR933X_DDR_REG_FLUSH_USB;
- } else
+ ath79_ip2_handler = ar933x_ip2_handler;
+ ath79_ip3_handler = ar933x_ip3_handler;
+ } else {
BUG();
+ }
cp0_perfcount_irq = ATH79_MISC_IRQ_PERFC;
mips_cpu_irq_init();