From 38ed55ca9ec2808ed7ee5183bec1f4e7187d3ea2 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sat, 25 Mar 2017 14:10:08 +0100 Subject: [PATCH] i2c: meson: improve interrupt handler and detect spurious interrupts If state is STATE_IDLE no interrupt should occur. Return IRQ_NONE if such a spurious interrupt is detected. Not having to take care of STATE_IDLE later in the interrupt handler allows to further simplify the interrupt handler in subsequent patches of this series. In addition move resetting REG_CTRL_START bit to the start of the interrupt handler to ensure that the start bit is always reset. Currently the start bit is not reset for STATE_STOP because i2c->state is set to STATE_IDLE. Signed-off-by: Heiner Kallweit Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-meson.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c index 0a9847c37a63..76aefd9264c2 100644 --- a/drivers/i2c/busses/i2c-meson.c +++ b/drivers/i2c/busses/i2c-meson.c @@ -231,12 +231,18 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id) spin_lock(&i2c->lock); meson_i2c_reset_tokens(i2c); + meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0); ctrl = readl(i2c->regs + REG_CTRL); dev_dbg(i2c->dev, "irq: state %d, pos %d, count %d, ctrl %08x\n", i2c->state, i2c->pos, i2c->count, ctrl); - if (ctrl & REG_CTRL_ERROR && i2c->state != STATE_IDLE) { + if (i2c->state == STATE_IDLE) { + spin_unlock(&i2c->lock); + return IRQ_NONE; + } + + if (ctrl & REG_CTRL_ERROR) { /* * The bit is set when the IGNORE_NAK bit is cleared * and the device didn't respond. In this case, the @@ -279,15 +285,12 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id) i2c->state = STATE_IDLE; complete(&i2c->done); break; - case STATE_IDLE: - break; } out: if (i2c->state != STATE_IDLE) { /* Restart the processing */ meson_i2c_write_tokens(i2c); - meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0); meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, REG_CTRL_START); } -- 2.39.2