[U-Boot] [PATCH 13/13] bootcount: i2c: Delay after writing

[Stefano Babic]

On 13/03/19 14:01, Heiko Schocher wrote:
> Hello Stefano,
> 
> Am 13.03.2019 um 11:04 schrieb Stefano Babic:
>> Hi Ian,
>>
>> On 31/01/19 15:21, Ian Ray wrote:
>>> Since 2018.11, the pattern of bootcount load and store has changed such
>>> that bootcount_inc() and bootcount_error() will load, increment, store,
>>> and load *again*.  The second load exposes a timing problem whereby the
>>> i2c read fails.  The root cause _seems_ to relate to performance of the
>>> 24c08 EEPROM.  Insert a delay after writing to work around this.
>>>
>>> Signed-off-by: Ian Ray <ian.ray at ge.com>
>>> ---
>>>   drivers/bootcount/bootcount_i2c.c | 4 ++++
>>>   1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/bootcount/bootcount_i2c.c
>>> b/drivers/bootcount/bootcount_i2c.c
>>> index ed22389..dd86426 100644
>>> --- a/drivers/bootcount/bootcount_i2c.c
>>> +++ b/drivers/bootcount/bootcount_i2c.c
>>> @@ -64,6 +64,10 @@ void bootcount_store(ulong a)
>>>               CONFIG_BOOTCOUNT_ALEN, buf, sizeof(buf));
>>>       if (ret != 0)
>>>           puts("Error writing bootcount\n");
>>> +    else
>>> +        /* Datasheet claims 2 ms typical write cycle time.
>>> +         * This delay ensures that next read will succeed. */
>>> +        mdelay(5);
>>>   
>>
>> I see, but this is device specific while bootcount_i2c should be
>> device-unaware. I know this driver is used with PMIC where no delay is
>> required. Heiko, is it ok to put a fix delay here or should be
>> configurable ?
> 
> I would prefer here to make this timeout configurable, thinking
> about boottime constraints.
> 

Right, I see the same - Ian, I have applied the whole series with the
exception of this one to u-boot-imx, next branch.

Regards,
Stefano

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