2020-06-30 08:01:47

by Gwendal Grignou

Subject: [PATCH] platform: chrome: Fix EC timestamp overflow

EC is using 32 bit timestamps (us), and before converting it to 64bit
they were not casted, so it would overflow every 4s.
Regular overflow every ~70 minutes was not taken into acoun either.

Signed-off-by: Gwendal Grignou <[email protected]>
---
drivers/platform/chrome/cros_ec_sensorhub_ring.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
index 23960f3acc0b1..641d91088cee2 100644
--- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c
+++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
@@ -465,9 +465,7 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
* Disable filtering since we might add more jitter
* if b is in a random point in time.
*/
- new_timestamp = fifo_timestamp -
- fifo_info->timestamp * 1000 +
- in->timestamp * 1000;
+ new_timestamp = c - b * 1000 + a * 1000;
/*
* The timestamp can be stale if we had to use the fifo
* info timestamp.
--
2.27.0.212.ge8ba1cc988-goog

2020-07-01 09:15:07

by Enric Balletbo i Serra

Subject: Re: [PATCH] platform: chrome: Fix EC timestamp overflow

Hi Gwendal,

Thank you for your patch.

On 30/6/20 9:52, Gwendal Grignou wrote:
> EC is using 32 bit timestamps (us), and before converting it to 64bit
> they were not casted, so it would overflow every 4s.
> Regular overflow every ~70 minutes was not taken into acoun either.
>
> Signed-off-by: Gwendal Grignou <[email protected]>

Applied for 5.9 with a slightly modified subject, platform/chrome:
cros_ec_sensorhub: ...

> ---
> drivers/platform/chrome/cros_ec_sensorhub_ring.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
> index 23960f3acc0b1..641d91088cee2 100644
> --- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c
> +++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
> @@ -465,9 +465,7 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
> * Disable filtering since we might add more jitter
> * if b is in a random point in time.
> */
> - new_timestamp = fifo_timestamp -
> - fifo_info->timestamp * 1000 +
> - in->timestamp * 1000;
> + new_timestamp = c - b * 1000 + a * 1000;
> /*
> * The timestamp can be stale if we had to use the fifo
> * info timestamp.
>