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

[Lee Jones]

On Fri, 24 Mar 2017, Enric Balletbo i Serra wrote:

> From: Vic Yang <victoryang@xxxxxxxxxx>
> 
> 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@xxxxxxxxxx>
> 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 to -fixes.

> 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
Linaro.org â Open source software for ARM SoCs
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