Hi,
Alexander Shishkin wrote:
Signed-off-by: Alexander Shishkin <[email protected]>
Could you add a better patch description? I.e. the patch is needed
because I2C failure can cause a kernel hang. The problem can be
reproduced by running the bus with wrong (too high) speed.
Also, you should send the patch to [email protected] with
linux-omap and [email protected] in CC.
Tested-by: Aaro Koskinen <[email protected]>
drivers/i2c/busses/i2c-omap.c | 21 +++++++++++++--------
1 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 75bf3ad..7617f18 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -803,15 +803,20 @@ complete:
*/
if (dev->rev <= OMAP_I2C_REV_ON_3430) {
- while (!(stat &
OMAP_I2C_STAT_XUDF)) {
- if (stat &
(OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
-
omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
- err |=
OMAP_I2C_STAT_XUDF;
- goto complete;
- }
- cpu_relax();
- stat =
omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+ unsigned long timeout = 10000;
I think 10000 reads (with L4 core interconnect latency) is at least 0.8 ms. It
should be more than
enough for normal cases.
+ while (!(stat & OMAP_I2C_STAT_XUDF) &&
--timeout) {
+ if (stat & (OMAP_I2C_STAT_NACK
| OMAP_I2C_STAT_AL)) {
+ omap_i2c_ack_stat(dev, stat
& (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
+ err |=
OMAP_I2C_STAT_XUDF;
+ goto complete;
}
+ cpu_relax();
+ stat = omap_i2c_read_reg(dev,
OMAP_I2C_STAT_REG);
+ }
+
+ if (!timeout)
+ dev_err(dev->dev, "timeout waiting
on XUDF bit\n");
}
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
A.
--
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
