Re: [PATCH 2/2] drivers: ipmi: Modify max length of IPMB packet

[Corey Minyard <minyard@acm.org>]

On Mon, Nov 11, 2019 at 06:36:10PM -0800, Vijay Khemka wrote:
> As per IPMB specification, maximum packet size supported is 255,
> modified Max length to 240 from 128 to accommodate more data.

I couldn't find this in the IPMB specification.

IIRC, the maximum on I2C is 32 byts, and table 6-9 in the IPMI spec,
under "IPMB Output" states: The IPMB standard message length is
specified as 32 bytes, maximum, including slave address.

I'm not sure where 128 came from, but maybe it should be reduced to 31.

-corey

> 
> Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
> ---
>  drivers/char/ipmi/ipmb_dev_int.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/char/ipmi/ipmb_dev_int.c b/drivers/char/ipmi/ipmb_dev_int.c
> index 2419b9a928b2..7f9198bbce96 100644
> --- a/drivers/char/ipmi/ipmb_dev_int.c
> +++ b/drivers/char/ipmi/ipmb_dev_int.c
> @@ -19,7 +19,7 @@
>  #include <linux/spinlock.h>
>  #include <linux/wait.h>
>  
> -#define MAX_MSG_LEN		128
> +#define MAX_MSG_LEN		240
>  #define IPMB_REQUEST_LEN_MIN	7
>  #define NETFN_RSP_BIT_MASK	0x4
>  #define REQUEST_QUEUE_MAX_LEN	256
> -- 
> 2.17.1
>