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Date:   Tue, 12 Nov 2019 06:48:45 -0600
From:   Corey Minyard <minyard@acm.org>
To:     Vijay Khemka <vijaykhemka@fb.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        openipmi-developer@lists.sourceforge.net,
        linux-kernel@vger.kernel.org, cminyard@mvista.com,
        asmaa@mellanox.com, joel@jms.id.au, linux-aspeed@lists.ozlabs.org,
        sdasari@fb.com
Subject: Re: [PATCH 2/2] drivers: ipmi: Modify max length of IPMB packet
Message-ID: <20191112124845.GE2882@minyard.net>
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References: <20191112023610.3644314-1-vijaykhemka@fb.com>
 <20191112023610.3644314-2-vijaykhemka@fb.com>
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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
>