From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Subject: Re: [PATCH] ata_piix: fix pio/mwdma programming (for testing, don't apply) Date: Sat, 3 Feb 2007 20:04:28 +0000 Message-ID: <20070203200428.4a7a5682@localhost.localdomain> References: <20070202151856.GD1625@htj.dyndns.org> <20070202174235.14b13f3e@localhost.localdomain> <45C3E7F0.6000506@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:34339 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751400AbXBCTwH (ORCPT ); Sat, 3 Feb 2007 14:52:07 -0500 In-Reply-To: <45C3E7F0.6000506@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: ahaas@airmail.net, linux-ide@vger.kernel.org > > Yep and if the BIOS programmed the slave into DMA that might not be ideal. > > How so? The bit will be programmed by set_dmamode() right after > set_piomode() is complete. IFF we also put the device into a DMA mode. A blacklisted device would be wrong. > See the difference? Smart one liners are dangerous. ?* is _much_ > better than cryptic arithmetic. Agreed > > >> * MWDMA mode programming cleared udma_mask even when the controller > >> doesn't support UDMA. This doesn't matter for your case. > > > > Or on the actual hardware. > > I was trying to make it more consistent with pio counterpart. We can > remove if() from set_piomode too. Let's just keep things in sync > between stuff including ide piix driver. The one you must not touch is the UDMA register rather than added UDMA bits in older registers. Alan