Re: [PATCH 1/7] mfd: cros-ec: Fix host command buffer size

Enric Balletbo i Serra
2017-04-03T15:12:19Z

On 03/04/17 16:30, Lee Jones wrote:
> On Mon, 03 Apr 2017, Lee Jones wrote:
>
>> On Fri, 24 Mar 2017, Enric Balletbo i Serra wrote:
>>
>>> From: Vic Yang <victoryang@google.com>
>>>
>>> For SPI, we can get up to 32 additional bytes for response preamble.
>>> The current overhead (2 bytes) may cause problems when we try to receive
>>> a big response. Update it to 32 bytes.
>>>
>>> Without this fix we could see a kernel BUG when we receive a big response
>>> from the Chrome EC when is connected via SPI.
>>>
>>> Signed-off-by: Vic Yang <victoryang@google.com>
>>> Tested-by: Enric Balletbo i Serra <enric.balletbo.collabora.com>
>>> ---
>>>
>>> This patch is a FIX, and I think that would be interesting see it merged
>>> in this release cycle. This should go through the MFD tree and can be picked
>>> independently of the other patches. Lee Jones I think this is for you.
>>>
>>> include/linux/mfd/cros_ec.h | 3 ++-
>>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> Applied, thanks.
>
> Scrap that, I'll keep it with the set.
>

Ok, I'll send a v2 asap with this patch and the few modifications requested on
patch 7/7. I'm wondering though if this specific patch could go with current
release cycle as (explained above) is a fix and current kernel is affected.

Thanks,
Enric

>>> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
>>> index b3e812f..3b16c90 100644
>>> --- a/include/linux/mfd/cros_ec.h
>>> +++ b/include/linux/mfd/cros_ec.h
>>> @@ -35,10 +35,11 @@
>>> * Max bus-specific overhead incurred by request/responses.
>>> * I2C requires 1 additional byte for requests.
>>> * I2C requires 2 additional bytes for responses.
>>> + * SPI requires up to 32 additional bytes for responses.
>>> * */
>>> #define EC_PROTO_VERSION_UNKNOWN 0
>>> #define EC_MAX_REQUEST_OVERHEAD 1
>>> -#define EC_MAX_RESPONSE_OVERHEAD 2
>>> +#define EC_MAX_RESPONSE_OVERHEAD 32
>>>
>>> /*
>>> * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
>>
>