-----Original Message----- From: Corey Minyard <tcminy...@gmail.com> On Behalf Of Corey Minyard Sent: Tuesday, November 12, 2019 3:30 PM To: Vijay Khemka <vijaykhe...@fb.com> Cc: Arnd Bergmann <a...@arndb.de>; Greg Kroah-Hartman <gre...@linuxfoundation.org>; openipmi-developer@lists.sourceforge.net; linux-ker...@vger.kernel.org; cminy...@mvista.com; Asmaa Mnebhi <as...@mellanox.com>; j...@jms.id.au; linux-asp...@lists.ozlabs.org; Sai Dasari <sdas...@fb.com> Subject: Re: [PATCH 2/2] drivers: ipmi: Modify max length of IPMB packet
On Tue, Nov 12, 2019 at 07:56:34PM +0000, Vijay Khemka wrote: > > > On 11/12/19, 4:48 AM, "Corey Minyard" <tcminy...@gmail.com on behalf of > miny...@acm.org> wrote: > > 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. > > We are using IPMI OEM messages and our response size is around 150 > bytes For some of responses. That's why I had set it to 240 bytes. Hmm. Well, that is a pretty significant violation of the spec, but there's nothing hard in the protocol that prohibits it, I guess. If Asmaa is ok with this, I'm ok with it, too. It doesn't bother me either. But I would like to do some experiment/testing first before validating it. I will get back to you. Vijay, how are you doing your testing? -corey > > I'm not sure where 128 came from, but maybe it should be reduced to 31. > > -corey > > > > > Signed-off-by: Vijay Khemka <vijaykhe...@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 > > > > _______________________________________________ Openipmi-developer mailing list Openipmi-developer@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openipmi-developer
