From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] libata: implement and use DMA mask configuration helper Date: Sun, 18 Mar 2007 13:47:48 -0400 Message-ID: <45FD7B44.5040509@garzik.org> References: <20070309104945.GG32687@htj.dyndns.org> <45F155E3.9040604@garzik.org> <45FD5154.9040603@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:45956 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999AbXCRRru (ORCPT ); Sun, 18 Mar 2007 13:47:50 -0400 In-Reply-To: <45FD5154.9040603@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: linux-ide@vger.kernel.org Tejun Heo wrote: > Jeff Garzik wrote: >> Tejun Heo wrote: >>> Implement and use DMA mask configuration helper. >>> >>> Signed-off-by: Tejun Heo >>> --- >>> This function probably belongs to pci layer. Put it in libata with >>> pci_test_bits() for the time being. >> AFAIK the default DMA mask is always 32-bit. Code (often written by me) >> that sets it to a 32-bit mask was just paranoia, and not really needed. >> >> Hence, the pci_go_64() function I added, found in #upstream. > > It isn't in #upstream yet. Also, at the second thought, there is a > problem with pci_go_64(). DMA masks are not reset after driver is > detached. Even if the device starts with 32bit DMA masks, after a 64bit > enabled driver is attached and detached, the device's DMA masks are > 64bit. I'm refreshing new-init-model patchset and keeping > pci_configure_dma_masks() for now. That "problem" has existed since day one, and nobody seems to care :) I can't think of a single 64-bit-capable driver that restores the masks, and can't think of a single bug report that resulted from it. Jeff