Under certain rare conditions, I2C_STAT[13].RDR bit may be set
and the corresponding interrupt fire, even there is no data in
the receive FIFO, or the I2C data transfer is still ongoing.
These spurious RDR events must be ignored by the software.
This patch handles and ignores RDR spurious interrupts.
Reviewed-by: Kalliguddi, Hema <hemahk@xxxxxx>
Signed-off-by: Manjunatha GK <manjugk@xxxxxx>
Cc: linux-omap@xxxxxxxxxxxxxxx
Cc: linux-i2c@xxxxxxxxxxxxxxx
Cc: ben-linux@xxxxxxxxx
Cc: Kalliguddi, Hema <hemahk@xxxxxx>
---
drivers/i2c/busses/i2c-omap.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index f2019d2..acf4076 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -796,6 +796,19 @@ complete:
}
if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
u8 num_bytes = 1;
+
+ /*
+ * OMAP3 I2C Errata ID: i207
+ * Under certain rare conditions, RDR could be set again
+ * when the bus is busy, then clear and ignore the interrupt
+ */
+ if (!(stat & OMAP_I2C_STAT_RRDY) && (stat &
+ OMAP_I2C_STAT_BB)) {
+ /* clear RDR */
+ omap_i2c_ack_stat(dev, stat & OMAP_I2C_STAT_RDR);
+ dev_err(dev->dev, "I2C: RDR when bus is busy.\n");
+ return IRQ_HANDLED;
+ }
if (dev->fifo_size) {
if (stat & OMAP_I2C_STAT_RRDY)
num_bytes = dev->fifo_size;
--
1.6.0.4
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
