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I2C: OMAP: NACK without STP 

On OMAP4 OMAP_I2C_STAT_NACK is causing a timeout on the next access.
The isr cleans all flags in OMAP_I2C_CON_REG by setting OMAP_I2C_CON_STP
OMAP_I2C_CON_STP is also set in omap_i2c_xfer_msg on the last message.

According to the TI TSR the sequence for OMAP_I2C_STAT_NACK and
OMAP_I2C_STAT_AL are nearly the same.
Removing the OMAP_I2C_CON_STP part in the isr fix the problem.
Tested on OMAP4430 and OMAP3530 (here NACK was not a problem)
Fixes also booting on 2430sdp.

Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
This commit is contained in:
Jan Weitzel 2011-12-07 11:50:16 -08:00 committed by Ben Dooks
parent 2727b17539
commit 78e1cf42ee
1 changed files with 2 additions and 4 deletions
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6
drivers/i2c/busses/i2c-omap.c
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@ -830,11 +830,9 @@ omap_i2c_isr(int this_irq, void *dev_id)
~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
if (stat & OMAP_I2C_STAT_NACK) {
if (stat & OMAP_I2C_STAT_NACK)
err |= OMAP_I2C_STAT_NACK;
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
OMAP_I2C_CON_STP);
}
if (stat & OMAP_I2C_STAT_AL) {
dev_err(dev->dev, "Arbitration lost\n");
err |= OMAP_I2C_STAT_AL;