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

Lee Jones
2017-04-03T14:30:26Z

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.

> > 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.
>

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
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