Messages in this thread Patch in this message | | | From | Federico Vaga <> | Subject | [PATCH 2/3] i2c:ocores: do not handle IRQ if IF is not set | Date | Mon, 25 Jun 2018 18:13:02 +0200 |
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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
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