From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: libata and DMA quirks Date: Fri, 27 Jun 2008 19:31:23 +1000 Message-ID: <1214559083.8011.544.camel@pasglop> References: <1214548895.8011.526.camel@pasglop> <4864A6C9.2050709@ru.mvista.com> <1214556703.8011.531.camel@pasglop> <4864AE92.2090805@ru.mvista.com> Reply-To: benh@kernel.crashing.org Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from gate.crashing.org ([63.228.1.57]:40298 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751181AbYF0Jbx (ORCPT ); Fri, 27 Jun 2008 05:31:53 -0400 In-Reply-To: <4864AE92.2090805@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Sergei Shtylyov Cc: linux-ide@vger.kernel.org, Jeff Garzik , Tejun Heo On Fri, 2008-06-27 at 13:10 +0400, Sergei Shtylyov wrote: > > It doesn't use DMA to transfer the bulk of ATAPI ? I know it uses PIO > > for the CDB but the rest of the transfer isn't done with DMA ? > > > Like I said, DMA is used only for the *block* transfer commands for > which the transfer size would always be a multiple of 16 bytes. Ok, I see. That might explain why I never saw a problem not doing anything special with drivers/ide. Cheers, Ben.