Resetting the bit 4 disables the interrupt delivery to the "secure
processor" core. This breaks the keyboard on a OLPC XO 1.75 laptop,
where the firmware running on the "secure processor" bit-bangs the
PS/2 protocol over the GPIO lines.

It is not clear what the rest of the bits are and Marvel was unhelpful
when asked for documentation. Aside from the SP bit, there are probably
priority bits.

Leaving the unknown bits as the firmware set them up seems to be a wiser
course of action compared to just turning them off.

Signed-off-by: Lubomir Rintel <[email protected]>
Acked-by: Pavel Machek <[email protected]>

---
Changes since v4:
- Remove unused ICU_INT_ROUTE_SP_IRQ define
- Try to further clarify the commit message

Changes since v3:
- Use #defined instead of integer literals

Changes since v2:
- Correct subsystem maintainers on Cc (irqchip)

Changes since v1:
- Adjusted wording & ack from Pavel
---
 drivers/irqchip/irq-mmp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-mmp.c b/drivers/irqchip/irq-mmp.c
index 37a54797a137..fac8f1365f76 100644
--- a/drivers/irqchip/irq-mmp.c
+++ b/drivers/irqchip/irq-mmp.c
@@ -34,6 +34,9 @@
 #define SEL_INT_PENDING                (1 << 6)
 #define SEL_INT_NUM_MASK       0x3f
 
+#define MMP2_ICU_INT_ROUTE_PJ4_IRQ     (1 << 5)
+#define MMP2_ICU_INT_ROUTE_PJ4_FIQ     (1 << 6)
+
 struct icu_chip_data {
        int                     nr_irqs;
        unsigned int            virq_base;
@@ -190,7 +193,8 @@ static const struct mmp_intc_conf mmp_conf = {
 static const struct mmp_intc_conf mmp2_conf = {
        .conf_enable    = 0x20,
        .conf_disable   = 0x0,
-       .conf_mask      = 0x7f,
+       .conf_mask      = MMP2_ICU_INT_ROUTE_PJ4_IRQ |
+                         MMP2_ICU_INT_ROUTE_PJ4_FIQ,
 };
 
 static void __exception_irq_entry mmp_handle_irq(struct pt_regs *regs)
-- 
2.20.1

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