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From: hkallweit1@gmail.com (Heiner Kallweit)
To: linus-amlogic@lists.infradead.org
Subject: [PATCH v2 4/5] media: rc: meson-ir: use readl_relaxed in the interrupt handler
Date: Wed, 12 Apr 2017 21:33:57 +0200	[thread overview]
Message-ID: <f44115e8-63de-2d8a-4864-1dff7e5b7a01@gmail.com> (raw)
In-Reply-To: <d5c18dbb-e86a-6b1c-1410-d6cc92dce711@gmail.com>

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 <hkallweit1@gmail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
---
v2:
- added R-b
---
 drivers/media/rc/meson-ir.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

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);
-- 
2.12.2

  parent reply	other threads:[~2017-04-12 19:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-12 19:26 [PATCH v2 0/5] media: rc: meson-ir: series with smaller improvements Heiner Kallweit
2017-04-12 19:28 ` [PATCH v2 1/5] media: rc: meson-ir: remove irq from struct meson_ir Heiner Kallweit
2017-04-12 19:30 ` [PATCH v2 2/5] media: rc: meson-ir: make use of the bitfield macros Heiner Kallweit
2017-04-12 19:32 ` [PATCH v2 3/5] media: rc: meson-ir: switch to managed rc device allocation / registration Heiner Kallweit
2017-04-12 19:33 ` Heiner Kallweit [this message]
2017-04-12 19:34 ` [PATCH v2 5/5] media: rc: meson-ir: change irq name to to of node name Heiner Kallweit

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