Date: Wed, 30 Oct 2002 20:47:10 +0000 From: Ian Dowse <iedowse@maths.tcd.ie> To: Luigi Rizzo <rizzo@icir.org> Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/dev/fxp if_fxp.c Message-ID: <200210302047.aa48208@salmon.maths.tcd.ie> In-Reply-To: Your message of "Wed, 30 Oct 2002 12:24:23 PST." <20021030122423.B24962@carp.icir.org>
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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
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