From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ilya Loginov Subject: Re: problems in commit 2d4dc890b5c8 (block: add helpers to run flush_dcache_page() against a bio and a request's pages) Date: Fri, 11 Dec 2009 00:27:00 +0300 Message-ID: <20091211002700.0600d327.isloginov@gmail.com> References: <1260398346.14369.45.camel@mulgrave.site> <20091210020309.36742c7f.isloginov@gmail.com> <1260400273.14369.52.camel@mulgrave.site> <20091210023609.b8c9bd34.isloginov@gmail.com> <1260402471.14369.60.camel@mulgrave.site> <20091210030638.db4cfd8a.isloginov@gmail.com> <1260404395.14369.68.camel@mulgrave.site> <20091210074020.a7c36c32.isloginov@gmail.com> <1260464851.2457.98.camel@mulgrave.site> <20091210224637.cb9712f7.isloginov@gmail.com> <1260476884.2457.116.camel@mulgrave.site> <20091210234816.5aca535e.isloginov@gmail.com> <1260478776.2457.141.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ew0-f219.google.com ([209.85.219.219]:34567 "EHLO mail-ew0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761030AbZLJV05 (ORCPT ); Thu, 10 Dec 2009 16:26:57 -0500 Received: by ewy19 with SMTP id 19so325038ewy.21 for ; Thu, 10 Dec 2009 13:27:03 -0800 (PST) In-Reply-To: <1260478776.2457.141.camel@mulgrave.site> Sender: linux-arch-owner@vger.kernel.org List-ID: To: James Bottomley Cc: Jens Axboe , linux-arch@vger.kernel.org On Thu, 10 Dec 2009 14:59:36 -0600 James Bottomley wrote: > To fix mips, you just need a > flush_kernel_dcache_page() in slram_read so that the alias is updated > after the memcpy. I think you right. But! If we choose this way: First. We need to realize flush_kernel_dcache_page() for many architectures. Am I right? Second. What difference will be between flush_kernel_dcache_page and flush_dcache_page on MIPS? In common, flush_dcache_page in MIPS set bit dirty on page. > I would also expect this driver not to work on any > highmem system without additional kmap/kunmap(_atomic) pairs in the read > and write routines. > How many other mtd drivers are affected, I'm not sure ... any that do > PIO are wrong ... those that do MMIO should be right (that looks to be > just the omap driver). Third. We should fix all other PIO drivers with problem and patch aoe: switch to the new bio_flush_dcache_pages() interface in -mm tree (i can't find this commit in the Linus tree). There is same problem. May be I wrong. And we have much less work. -- Ilya Loginov