i2c-omap: Fix I2C status ACK

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.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Moiz Sonasath <m-sonasath@ti.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

drivers/i2c/busses/i2c-omap.c

@@ -674,7 +674,14 @@ omap_i2c_isr(int this_irq, void *dev_id)
 
 		err = 0;
 complete:
-		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
+		/*
+		 * Ack the stat in one go, but [R/X]DR and [R/X]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));
 
 		if (stat & OMAP_I2C_STAT_NACK) {
 			err |= OMAP_I2C_STAT_NACK;