From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Snook Subject: Re: [atl1-devel] [PATCH 2/2] atl1: wrap problematic optimizations in CONFIG_ATL1_EXPERIMENTAL Date: Fri, 07 Sep 2007 20:27:31 -0400 Message-ID: <46E1EC73.80704@redhat.com> References: <46E1E1AC.5030801@redhat.com> <20070907235209.GB12055@shell.boston.redhat.com> <68676e00709071721g35c07b0by58991c56e17ec442@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Jeff Garzik , atl1-devel@lists.sourceforge.net, netdev@vger.kernel.org To: Luca Return-path: Received: from mx1.redhat.com ([66.187.233.31]:33036 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551AbXIHA1k (ORCPT ); Fri, 7 Sep 2007 20:27:40 -0400 In-Reply-To: <68676e00709071721g35c07b0by58991c56e17ec442@mail.gmail.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Luca wrote: > On 9/8/07, Chris Snook wrote: >> From: Chris Snook >> >> Make certain problematic optimizations build-time configurable. >> >> Signed-off-by: Chris Snook >> Acked-by: Jay Cliburn >> >> --- a/drivers/net/atl1/atl1_main.c 2007-09-04 10:12:38.000000000 -0400 >> +++ b/drivers/net/atl1/atl1_main.c 2007-09-04 11:23:26.000000000 -0400 >> @@ -2203,22 +2203,26 @@ static int __devinit atl1_probe(struct p >> struct net_device *netdev; >> struct atl1_adapter *adapter; >> static int cards_found = 0; >> - bool pci_using_64 = true; >> + bool pci_using_64 = false; >> int err; >> >> err = pci_enable_device(pdev); >> if (err) >> return err; >> >> +#ifdef CONFIG_ATL1_EXPERIMENTAL >> err = pci_set_dma_mask(pdev, DMA_64BIT_MASK); >> + if (!err) { >> + pci_using_64 = true; >> + goto dma_ok; >> + } >> +#endif /* CONFIG_ATL1_EXPERIMENTAL */ > > This is more like CONFIG_ATL1_PLEASE_KILL_MY_MACHINE; I really don't > see the problem with just limiting the DMA mask: > - if you don't have physical mem over the 4GB boundary limiting DMA > doesn't make any difference > - if you have more than 4GB of memory the machine won't survive long without it Atheros is still working on this, and we plan to fix it. 64-bit DMA *should* work. I just resubmitted your patch with the comment Jeff requested. I still may want to revisit CONFIG_ATL1_EXPERIMENTAL soon when I start playing around with more features. -- Chris