ARDY|NACK and ARDY|AL are set together in OMAP_I2C_STAT_REG, which will be
processed incorrectly now:
iterration 1:
- I2C irq triggered (ARDY|NACK)
- omap_i2c_isr_thread() will ask NACK, fill dev->cmd_err = OMAP_I2C_STAT_NACK
and trigger "cmd_complete" completion.
- omap_i2c_xfer_msg() will be unblocked, hande NACK and finish its execution.
- omap_i2c_xfer() will finish
iteration 2:
- I2C irq triggered (ARDY)
- omap_i2c_isr_thread() will ask ARDY, trigger completion
At this point dev->cmd_err == OMAP_I2C_STAT_NACK, "cmd_complete" is not
initialized and omap_i2c_xfer() may be completed at all.
So, I2C driver is not ready for iteration 2.
Hence, fix it by asking NACK, AL and ARDY all togather in omap_i2c_isr_thread()
before unblocking omap_i2c_xfer_msg() execution.
This is the "old" I2C interrupt handler behavior which was changed by commit:
1d7afc95946487945cc7f5019b41255b72224b70 "i2c: omap: ack IRQ in parts".
CC: Kevin Hilman <khilman@xxxxxxxxxx>
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
drivers/i2c/busses/i2c-omap.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 2dac598..46fb8a5 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -938,17 +938,15 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
break;
}
+ omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL);
+
if (stat & OMAP_I2C_STAT_NACK) {
err |= OMAP_I2C_STAT_NACK;
- omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
- break;
}
if (stat & OMAP_I2C_STAT_AL) {
dev_err(dev->dev, "Arbitration lost\n");
err |= OMAP_I2C_STAT_AL;
- omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL);
- break;
}
/*
--
1.7.9.5
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