[patch 09/12] MIPS/ath91: Remove pointless irqdisable/enable

From: Thomas Gleixner
Date: Mon Jul 13 2015 - 16:47:22 EST


The various interrupt flow handlers in ath79 are cascading interrupt
handlers. They all have a disable_irq_nosync()/enable_irq() pair
around the generic_handle_irq() call. The value of this disable/enable
is zero because its a complete noop:

disable_irq_nosync() merily increments the disable count without
actually masking the interrupt. enable_irq() soleley decrements the
disable count without touching the interrupt chip. The interrupt
cannot arrive again because the complete call chain runs with
interrupts disabled.

Remove it.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
arch/mips/ath79/irq.c | 18 ++----------------
1 file changed, 2 insertions(+), 16 deletions(-)

Index: tip/arch/mips/ath79/irq.c
===================================================================
--- tip.orig/arch/mips/ath79/irq.c
+++ tip/arch/mips/ath79/irq.c
@@ -124,8 +124,6 @@ static void ar934x_ip2_irq_dispatch(unsi
{
u32 status;

- disable_irq_nosync(irq);
-
status = ath79_reset_rr(AR934X_RESET_REG_PCIE_WMAC_INT_STATUS);

if (status & AR934X_PCIE_WMAC_INT_PCIE_ALL) {
@@ -137,8 +135,6 @@ static void ar934x_ip2_irq_dispatch(unsi
} else {
spurious_interrupt();
}
-
- enable_irq(irq);
}

static void ar934x_ip2_irq_init(void)
@@ -157,14 +153,12 @@ static void qca955x_ip2_irq_dispatch(uns
{
u32 status;

- disable_irq_nosync(irq);
-
status = ath79_reset_rr(QCA955X_RESET_REG_EXT_INT_STATUS);
status &= QCA955X_EXT_INT_PCIE_RC1_ALL | QCA955X_EXT_INT_WMAC_ALL;

if (status == 0) {
spurious_interrupt();
- goto enable;
+ return;
}

if (status & QCA955X_EXT_INT_PCIE_RC1_ALL) {
@@ -176,17 +170,12 @@ static void qca955x_ip2_irq_dispatch(uns
/* TODO: flush DDR? */
generic_handle_irq(ATH79_IP2_IRQ(1));
}
-
-enable:
- enable_irq(irq);
}

static void qca955x_ip3_irq_dispatch(unsigned int irq, struct irq_desc *desc)
{
u32 status;

- disable_irq_nosync(irq);
-
status = ath79_reset_rr(QCA955X_RESET_REG_EXT_INT_STATUS);
status &= QCA955X_EXT_INT_PCIE_RC2_ALL |
QCA955X_EXT_INT_USB1 |
@@ -194,7 +183,7 @@ static void qca955x_ip3_irq_dispatch(uns

if (status == 0) {
spurious_interrupt();
- goto enable;
+ return;
}

if (status & QCA955X_EXT_INT_USB1) {
@@ -211,9 +200,6 @@ static void qca955x_ip3_irq_dispatch(uns
/* TODO: flush DDR? */
generic_handle_irq(ATH79_IP3_IRQ(2));
}
-
-enable:
- enable_irq(irq);
}

static void qca955x_irq_init(void)


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