From: Federico Vaga <federico.vaga@cern.ch>
To: <linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
"Peter Korsgaard" <jacmet@sunsite.dk>
Cc: <federico.vaga@cern.ch>
Subject: [PATCH 2/3] i2c:ocores: do not handle IRQ if IF is not set
Date: Mon, 25 Jun 2018 18:13:02 +0200 [thread overview]
Message-ID: <20180625161303.7991-3-federico.vaga@cern.ch> (raw)
In-Reply-To: <20180625161303.7991-1-federico.vaga@cern.ch>
If the Interrupt Flag (IF) is not set, we should not handle the IRQ:
- the line can be shared with other devices
- it can be a spurious interrupt
To avoid reading twice the status register, the ocores_process() function
expects it to be read by the caller.
Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
---
drivers/i2c/busses/i2c-ocores.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index 98c0ef74882b..274d6eb22a2c 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -139,10 +139,9 @@ static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
return i2c->getreg(i2c, reg);
}
-static void ocores_process(struct ocores_i2c *i2c)
+static void ocores_process(struct ocores_i2c *i2c, u8 stat)
{
struct i2c_msg *msg = i2c->msg;
- u8 stat = oc_getreg(i2c, OCI2C_STATUS);
if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) {
/* stop has been sent */
@@ -209,9 +208,13 @@ static void ocores_process(struct ocores_i2c *i2c)
static irqreturn_t ocores_isr(int irq, void *dev_id)
{
struct ocores_i2c *i2c = dev_id;
+ u8 stat = oc_getreg(i2c, OCI2C_STATUS);
unsigned long flags;
int ret;
+ if (!(stat & OCI2C_STAT_IF))
+ return IRQ_NONE;
+
/*
* We need to protect i2c against a timeout event (see ocores_xfer())
* If we cannot take this lock, it means that we are already in
@@ -222,7 +225,7 @@ static irqreturn_t ocores_isr(int irq, void *dev_id)
if (!ret)
return IRQ_HANDLED;
- ocores_process(i2c);
+ ocores_process(i2c, stat);
spin_unlock_irqrestore(&i2c->xfer_lock, flags);
--
2.15.0
next prev parent reply other threads:[~2018-06-25 16:13 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-25 16:13 i2c:ocores: fixes and polling mechanism Federico Vaga
2018-06-25 16:13 ` [PATCH 1/3] i2c:ocores: stop transfer on timeout Federico Vaga
2018-10-21 14:10 ` Peter Korsgaard
2018-10-24 14:51 ` Federico Vaga
2018-10-26 17:46 ` Peter Korsgaard
2018-10-25 7:42 ` Federico Vaga
2018-06-25 16:13 ` Federico Vaga [this message]
2018-10-21 14:12 ` [PATCH 2/3] i2c:ocores: do not handle IRQ if IF is not set Peter Korsgaard
2018-10-29 8:53 ` Wolfram Sang
2018-10-29 14:27 ` Federico Vaga
2018-06-25 16:13 ` [PATCH 3/3] i2c:ocores: add polling interface Federico Vaga
2018-10-21 14:39 ` Peter Korsgaard
2018-10-24 9:51 ` Federico Vaga
2018-10-26 17:45 ` Peter Korsgaard
2018-10-29 8:50 ` Federico Vaga
2018-10-29 13:04 ` Peter Korsgaard
2018-10-29 13:11 ` Federico Vaga
2018-10-25 7:47 ` Federico Vaga
2018-08-11 17:13 ` i2c:ocores: fixes and polling mechanism Federico Vaga
2018-08-12 15:34 ` Wolfram Sang
2018-08-22 16:16 ` Peter Korsgaard
2018-09-17 16:42 ` Wolfram Sang
2018-09-19 5:15 ` Peter Korsgaard
2018-09-19 6:51 ` Wolfram Sang
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