From owner-cvs-all Wed Oct 30 12:47:15 2002 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6A36137B412; Wed, 30 Oct 2002 12:47:14 -0800 (PST) Received: from salmon.maths.tcd.ie (salmon.maths.tcd.ie [134.226.81.11]) by mx1.FreeBSD.org (Postfix) with SMTP id CEF5F43E4A; Wed, 30 Oct 2002 12:47:12 -0800 (PST) (envelope-from iedowse@maths.tcd.ie) Received: from walton.maths.tcd.ie by salmon.maths.tcd.ie with SMTP id ; 30 Oct 2002 20:47:11 +0000 (GMT) To: Luigi Rizzo Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/dev/fxp if_fxp.c In-Reply-To: Your message of "Wed, 30 Oct 2002 12:24:23 PST." <20021030122423.B24962@carp.icir.org> Date: Wed, 30 Oct 2002 20:47:10 +0000 From: Ian Dowse Message-ID: <200210302047.aa48208@salmon.maths.tcd.ie> Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message <20021030122423.B24962@carp.icir.org>, Luigi Rizzo writes: >actually, before people get alarmed by this commit message, >i want to make a clarification. > >The status field is updated only on descriptors marked as >'completed' by the card, so they are not be in use by >the hardware while the driver touches it. Sorry, you're right there - the bit about it writing at the same time as the hardware is incorrect. However if the 0x4000 bit gets set (and there is no documentation that says it won't be), it is possible for the RNR recovery code to be executed while the hardware is still receiving packets: fxp_scb_wait(sc); CSR_WRITE_4(sc, FXP_CSR_SCB_GENERAL, vtophys(sc->rfa_headm->m_ext.ext_buf) + RFA_ALIGNMENT_FUDGE); fxp_scb_cmd(sc, FXP_SCB_COMMAND_RU_START); This is probably not good. Ian To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message