I2C status ack for [RX]RDR and [RX]RDY could cause race conditions of clearing the event twice and a violation of the programing sequence as defined in TRM This patch fixes the same.
Issue identified by Jagadeesh Pakaravoor and Ulrik Bech Hald. Signed-off-by: Nishanth Menon <[email protected]> --- drivers/i2c/busses/i2c-omap.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index ece0125..0db0051 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -651,7 +651,14 @@ omap_i2c_isr(int this_irq, void *dev_id) break; } - omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); + /* + * Ack the stat in one go, but [rx]dr and [rx]rdy should be + * acked after the data operation is complete. + * Ref: TRM SWPU114Q Figure 18-31 + */ + omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat & + ~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR | + OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); err = 0; if (stat & OMAP_I2C_STAT_NACK) { -- 1.5.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
