Re: [PATCH v2 5/7] mfd: cros_ec: wait for completion of commands that return IN_PROGRESS

[Andrew Bresticker <abrestic@chromium.org>]

On Mon, Sep 8, 2014 at 4:39 AM, Javier Martinez Canillas
<javier.martinez@collabora.co.uk> wrote:
> Hello Lee,
>
> On 09/04/2014 10:34 AM, Lee Jones wrote:
>> On Mon, 25 Aug 2014, Javier Martinez Canillas wrote:
>>> From: Andrew Bresticker <abrestic@chromium.org>
>>>
>>> When an EC command returns EC_RES_IN_PROGRESS, we need to query
>>> the state of the EC until it indicates that it is no longer busy.
>>> Do this in cros_ec_cmd_xfer() under the EC's mutex so that other
>>> commands (e.g. keyboard, I2C passtru) aren't issued to the EC while
>>> it is working on the in-progress command.
>>>
>>> Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
>>> Reviewed-by: Simon Glass <sjg@chromium.org>
>>> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
>>> ---
>>>
>>> Changes since v1:
>>>  - The *xfer() calls don't modify the passed cros_ec_command so there is
>>>    no need to populate it inside the for loop. Suggested by Lee Jones.
>>> ---
>>>  drivers/mfd/cros_ec.c | 34 +++++++++++++++++++++++++++++++++-
>>>  1 file changed, 33 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
>>> index c53804a..cd0c93c 100644
>>> --- a/drivers/mfd/cros_ec.c
>>> +++ b/drivers/mfd/cros_ec.c
>>> @@ -23,6 +23,10 @@
>>>  #include <linux/mfd/core.h>
>>>  #include <linux/mfd/cros_ec.h>
>>>  #include <linux/mfd/cros_ec_commands.h>
>>> +#include <linux/delay.h>
>>> +
>>> +#define EC_COMMAND_RETRIES  50
>>> +#define EC_RETRY_DELAY_MS   10
>>
>> Where did these values come from?
>>
>
> These patches were taken from the ChromeOS 3.8 kernel so I don't really know
> why these values were chosen. I'll let Andrew or one of the ChromiumOS folks
> to answer this question.

These are the values flashrom used when retrying commands.