From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH] mmci: handle clock frequency 0 properly Date: Wed, 17 Nov 2010 00:34:29 +0000 Message-ID: <20101117003429.GA2578@void.printf.net> References: <1289927869-14519-1-git-send-email-linus.walleij@stericsson.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from void.printf.net ([89.145.121.20]:56516 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753459Ab0KQAec (ORCPT ); Tue, 16 Nov 2010 19:34:32 -0500 Content-Disposition: inline In-Reply-To: <1289927869-14519-1-git-send-email-linus.walleij@stericsson.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Linus Walleij Cc: linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Russell King Hi Linus, On Tue, Nov 16, 2010 at 06:17:49PM +0100, Linus Walleij wrote: > This removes the default clocking for the MMCI controller so that > the external MCI card clock does not activate until the first > .set_ios() call is issued. It will further handle the transitions > from a clock != 0 to 0 and vice versa by gating/ungating the > clock with clk_disable()/clk_enable(). > > This assures that the MCI clock will not be active unless there > is a card in the MMC slot. > > By default the MMC core will not gate off the clock to a card > once it's enabled, but with the separate patch for aggressive > clocking this can optionally be enabled for the system. > > Cc: Chris Ball > Cc: Russell King > Signed-off-by: Linus Walleij > --- > Changes since v8: > > The frequency registers shall be set with mmci_set_clkreg() > no matter whether the clock gets enabled or disabled, systems > without a clk framework will need this so that the clock > dividers are set to the apropriate values for clock 0 as > well, and that will probably mitigate power consumption > somewhat on these systems. > > Chris: this is a new version after Russell found an error in > it. Can you please take the old version of this patch out of > the MMC tree so I can merge it through Russells ARM tree > instead? The patches are perfectly orthogonal so it doesn't > need to live in the MMC tree. Okay, this patch has been removed from mmc-next now. (I'm holding off on pulling the rest of your latest patchset until you reply to David Vrabel's review of [2/3] -- let me know if you think it should be pulled now instead.) Thanks, -- Chris Ball One Laptop Per Child From mboxrd@z Thu Jan 1 00:00:00 1970 From: cjb@laptop.org (Chris Ball) Date: Wed, 17 Nov 2010 00:34:29 +0000 Subject: [PATCH] mmci: handle clock frequency 0 properly In-Reply-To: <1289927869-14519-1-git-send-email-linus.walleij@stericsson.com> References: <1289927869-14519-1-git-send-email-linus.walleij@stericsson.com> Message-ID: <20101117003429.GA2578@void.printf.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Linus, On Tue, Nov 16, 2010 at 06:17:49PM +0100, Linus Walleij wrote: > This removes the default clocking for the MMCI controller so that > the external MCI card clock does not activate until the first > .set_ios() call is issued. It will further handle the transitions > from a clock != 0 to 0 and vice versa by gating/ungating the > clock with clk_disable()/clk_enable(). > > This assures that the MCI clock will not be active unless there > is a card in the MMC slot. > > By default the MMC core will not gate off the clock to a card > once it's enabled, but with the separate patch for aggressive > clocking this can optionally be enabled for the system. > > Cc: Chris Ball > Cc: Russell King > Signed-off-by: Linus Walleij > --- > Changes since v8: > > The frequency registers shall be set with mmci_set_clkreg() > no matter whether the clock gets enabled or disabled, systems > without a clk framework will need this so that the clock > dividers are set to the apropriate values for clock 0 as > well, and that will probably mitigate power consumption > somewhat on these systems. > > Chris: this is a new version after Russell found an error in > it. Can you please take the old version of this patch out of > the MMC tree so I can merge it through Russells ARM tree > instead? The patches are perfectly orthogonal so it doesn't > need to live in the MMC tree. Okay, this patch has been removed from mmc-next now. (I'm holding off on pulling the rest of your latest patchset until you reply to David Vrabel's review of [2/3] -- let me know if you think it should be pulled now instead.) Thanks, -- Chris Ball One Laptop Per Child