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On snow, there are reports of the following warning in the i2c master reciever code: Stop event deadline passed: CR1=0000001000000001 I've been running this torture test, and even with the timeout feature completely removed, it never hangs. The stop bit is always sent eventually, even through thousands and thousands of transactions (of which a couple take too long for the current timeout). I timed a lot of these and it looks like the vast majority are fine but just a few are really really slow. To this end, I'm increasing the timeout. It seems that the wait loop is getting preempted for a while before it can go back and check, causing these timeout messages. So every now and then the process get pre-empted for a long time causing what looks like a long timeout. The thing is, the stop bit is always getting sent, we're just not noticing for a while. So even in the really slow cases, everything should be fine. Since the bit's getting sent either way, it seems like increasing the timeout all but fixes the problem where the EC thinks it didn't send. However, since the timeout is quite high now, I added a sleep in the busy loop so that if a message is messed up and the stop bit doesn't send, the task won't steal the cpu for the entire time. Note: This also fixes a bug in the i2c error handler where it was trying to print ints and strings and ads a little more information to the timeout warning in case it starts showing up again. BUG=chrome-os-partner:12742 TEST=From the EC console run "battery 100000" while running "while true; do /usr/local/sbin/i2cdump -f -y 4 0x48; done" to seriously stress test the i2c bus. Then reboot the machine several times. There should be no Stop bit warnings, or failed i2c transfers BRANCH=snow Change-Id: I590a9458783d16e57987102b1ec1299d5ddb0fa2 Signed-off-by: Charlie Mooney <charliemooney@chromium.org> Reviewed-on: https://gerrit.chromium.org/gerrit/31024 Reviewed-by: David Hendricks <dhendrix@chromium.org>