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

From: Corey Minyard
Date: Tue Nov 12 2019 - 07:48:50 EST


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@xxxxxx>
> ---
> 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
>