From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: [PATCH v4 07/10] i2c: meson: improve interrupt handler and detect spurious interrupts Date: Tue, 14 Mar 2017 22:51:40 +0100 Message-ID: References: <1a2ecdc8-a326-a7a7-22ec-658fd147daf4@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wr0-f193.google.com ([209.85.128.193]:33095 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753114AbdCNVya (ORCPT ); Tue, 14 Mar 2017 17:54:30 -0400 Received: by mail-wr0-f193.google.com with SMTP id g10so25528364wrg.0 for ; Tue, 14 Mar 2017 14:54:29 -0700 (PDT) In-Reply-To: <1a2ecdc8-a326-a7a7-22ec-658fd147daf4@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 --- 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 3fc1a715..0b09e059 100644 --- a/drivers/i2c/busses/i2c-meson.c +++ b/drivers/i2c/busses/i2c-meson.c @@ -228,12 +228,18 @@ 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 @@ -276,15 +282,12 @@ 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