From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Dreier Subject: Re: [PATCH] mlx4/IB: Add set_4k_mtu module parameter. Date: Tue, 12 Jan 2010 09:05:06 -0800 Message-ID: References: <20100112120901.GA7161@vlad-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20100112120901.GA7161@vlad-laptop> (Vladimir Sokolovsky's message of "Tue, 12 Jan 2010 14:09:02 +0200") Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: vlad-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org I'm not thrilled about this patch. > +module_param_named(set_4k_mtu, mlx4_ib_set_4k_mtu, int, 0444); > +MODULE_PARM_DESC(set_4k_mtu, "attempt to set 4K MTU to all ConnectX ports"); What does "attempt to set 4K MTU" mean? Try to set the MTU cap to 4K? What happens if it fails? Is there any reason not to just let the MTU cap be 4K all time? Having this be a module parameter really seems like a bad idea for the future.... > + if (mlx4_ib_set_4k_mtu) > + ((__be32 *) mailbox->buf)[0] |= cpu_to_be32((1 << 22) | > + (1 << 21) | > + (5 << 12) | > + (2 << 4)); Is there any way for this to write this with fewer unexplained magic numbers? - R. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html