From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: [RFC PATCH 2/4] pio-mapping: Add ARM support for the PIO mapping API Date: Mon, 8 Feb 2010 16:54:17 +0000 Message-ID: <20100208165417.GA29551@flint.arm.linux.org.uk> References: <20100205163044.30827.10915.stgit@pc1117.cambridge.arm.com> <20100205163154.30827.6636.stgit@pc1117.cambridge.arm.com> <1265388234.14404.47.camel@mulgrave.site> <1265390403.7692.101.camel@pc1117.cambridge.arm.com> <1265391384.14404.53.camel@mulgrave.site> <1265645421.4020.119.camel@pc1117.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:51427 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753529Ab0BHQye (ORCPT ); Mon, 8 Feb 2010 11:54:34 -0500 Content-Disposition: inline In-Reply-To: <1265645421.4020.119.camel@pc1117.cambridge.arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Catalin Marinas Cc: James Bottomley , linux-arch@vger.kernel.org On Mon, Feb 08, 2010 at 04:10:21PM +0000, Catalin Marinas wrote: > The pio_data_direction could be dropped and use the DMA one. We could > also use pio_kmap_read/pio_kmap_write or similar but we have to triple > the number of functions, so I prefer the additional argument. Do we need to do anything for reading a buffer for PIO _out_ to the device? My understanding is that this has never been a problem. The only problem I'm aware of is where PIO writes to the kernel mapping of a lowmem pages; highmem pages need the data flushed out of the temporary atomic kmap mapping anyway. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: