From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: [PATCH v5 07/10] i2c: meson: improve interrupt handler and detect spurious interrupts Date: Sat, 25 Mar 2017 14:10:08 +0100 Message-ID: <3248cfbd-a6be-06ac-47be-d7f3e8239996@gmail.com> References: <645519b8-93e6-57b1-ae8f-7804c6beb9b1@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:36083 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750718AbdCYNOn (ORCPT ); Sat, 25 Mar 2017 09:14:43 -0400 Received: by mail-wm0-f66.google.com with SMTP id x124so2846407wmf.3 for ; Sat, 25 Mar 2017 06:14:41 -0700 (PDT) In-Reply-To: <645519b8-93e6-57b1-ae8f-7804c6beb9b1@gmail.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Wolfram Sang , Jerome Brunet , Kevin Hilman Cc: "linux-i2c@vger.kernel.org" , linux-amlogic@lists.infradead.org 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 --- v2: - don't print an error if spurious interrupt is detected v3: - don't remove a start bit reset, we need it to properly handle timeouts - extend commit message v4: - no changes v5: - no changes --- 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 f7d3fa32..081d5b0c 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); } -- 2.12.0