From: mattias.wallin@stericsson.com (Mattias Wallin) Date: Thu, 7 Apr 2011 09:29:57 +0200 Subject: [PATCHv5 1/3] ARM: Translate delay.S into (mostly) C In-Reply-To: <1302047800-26720-2-git-send-email-sboyd@codeaurora.org> References: <1302047800-26720-1-git-send-email-sboyd@codeaurora.org> <1302047800-26720-2-git-send-email-sboyd@codeaurora.org> Message-ID: <4D9D67F5.8030703@stericsson.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04/06/2011 01:56 AM, Stephen Boyd wrote: > We want to allow machines to override the __delay() implementation > at runtime so they can use a timer based __delay() routine. It's > easier to do this using C, so let's write udelay and friends in C. > > We lose the #if 0 code, which according to Russell is used "to > make the delay loop more stable and predictable on older CPUs" > (seehttp://article.gmane.org/gmane.linux.kernel/888867 for more > info). We shouldn't be too worried though, since we'll soon add > functionality allowing a machine to set the __delay() loop > themselves, thus allowing machines to resurrect the commented out > code should they need it. > > Nicolas expressed concern that fixed lpj cmdlines will break due to > compiler optimizations. That doesn't seem to be the case since > before and after this patch I get the same lpj value when running > my CPU at 19.2 MHz. That should be sufficiently slow enough to > cover any machine running Linux. Tested-by: Mattias Wallin Yours, Mattias Wallin