[v2,4/5] media: rc: meson-ir: use readl_relaxed in the interrupt handler

Commit Message

Heiner Kallweit April 12, 2017, 7:33 p.m. UTC

We don't need the memory barriers here and an interrupt handler should
be as fast as possible. Therefore switch to readl_relaxed.

Signed-off-by: Heiner Kallweit <[e-mail]>
Reviewed-by: Neil Armstrong <[e-mail]>
---
v2:
- added R-b
---
 drivers/media/rc/meson-ir.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Patch

diff --git a/drivers/media/rc/meson-ir.c b/drivers/media/rc/meson-ir.c
index cf8943d2..1c72593d 100644
--- a/drivers/media/rc/meson-ir.c
+++ b/drivers/media/rc/meson-ir.c
@@ -83,16 +83,17 @@  static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
 static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
 {
 	struct meson_ir *ir = dev_id;
-	u32 duration;
+	u32 duration, status;
 	DEFINE_IR_RAW_EVENT(rawir);
 
 	spin_lock(&ir->lock);
 
-	duration = readl(ir->reg + IR_DEC_REG1);
+	duration = readl_relaxed(ir->reg + IR_DEC_REG1);
 	duration = FIELD_GET(REG1_TIME_IV_MASK, duration);
 	rawir.duration = US_TO_NS(duration * MESON_TRATE);
 
-	rawir.pulse = !!(readl(ir->reg + IR_DEC_STATUS) & STATUS_IR_DEC_IN);
+	status = readl_relaxed(ir->reg + IR_DEC_STATUS);
+	rawir.pulse = !!(status & STATUS_IR_DEC_IN);
 
 	ir_raw_event_store_with_filter(ir->rc, &rawir);
 	ir_raw_event_handle(ir->rc);