Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752527Ab0H1P14 (ORCPT ); Sat, 28 Aug 2010 11:27:56 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:34324 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752305Ab0H1P1z convert rfc822-to-8bit (ORCPT ); Sat, 28 Aug 2010 11:27:55 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:organization:to:subject:date:user-agent:cc:references :in-reply-to:mime-version:content-type:content-transfer-encoding :message-id; b=cIY7EbFH/lc4Z+kXbTtUZ2faYxyaYmAzCzk8uI7Q+NyVz6XRbk/DNU5sxmuhnT9HG5 4y8ULJLOZ/MyigqFOcuT9tL5Nj5Gn27Mw4bGCzBeqFqFKZYpX3Kms8zJpTtDPp993Pr4 9+utmX9fKv8Bh5kXxStqiXv/ACl8t1+gagSiU= From: Marek Vasut Organization: Hack&Dev To: linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 3/3 v2] dmaengine: Add Freescale i.MX SDMA support Date: Sat, 28 Aug 2010 17:27:10 +0200 User-Agent: KMail/1.13.3 (Linux/2.6.34-1-amd64; KDE/4.4.4; x86_64; ; ) Cc: Linus Walleij , "Uwe =?iso-8859-1?q?Kleine-K=F6nig?=" , Sascha Hauer , Dan Williams , linux-kernel@vger.kernel.org References: <1281956870-12463-1-git-send-email-s.hauer@pengutronix.de> <20100823174852.GB26928@pengutronix.de> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Message-Id: <201008281727.10913.marek.vasut@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1265 Lines: 36 Dne So 28. srpna 2010 17:18:17 Linus Walleij napsal(a): > 2010/8/23 Uwe Kleine-K?nig : > >> + evt = readl(SDMA_H_EVTOVR); > >> + mcu = readl(SDMA_H_HOSTOVR); > >> + dsp = readl(SDMA_H_DSPOVR); > > > > __raw_readl? > > Sorry I never understood this __raw_[read|write][b|w|l] vs. > plain read[b|w|l] proliferation in some drivers and code. > > What's the reason for? Hey, this trick is, if you create the VA<->PA mapping at the kernel start (eg. see how pxa_map_io() is replacedon some devices for instance), you then use the VA address you specified and use __raw_{read,write}[b,w,l](). So use __raw_{read,write}[b,w,l]() on drivers specific for certain device and use {read,write}[b,w,l]() on ioremap()ed memory areas, aka. in common drivers. Cheers > > Yours, > Linus Walleij > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/