From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH 1/1] mmc: sdhci-esdhc: Change delay after setting clock from 100ms to 1ms Date: Thu, 01 Dec 2011 13:10:33 -0500 Message-ID: <87vcq0kvs6.fsf@laptop.org> References: <1321944150-12162-1-git-send-email-tony.lin@freescale.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from void.printf.net ([89.145.121.20]:50778 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753524Ab1LASKa (ORCPT ); Thu, 1 Dec 2011 13:10:30 -0500 In-Reply-To: <1321944150-12162-1-git-send-email-tony.lin@freescale.com> (Tony Lin's message of "Tue, 22 Nov 2011 14:42:30 +0800") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Tony Lin Cc: linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, X.Xie@freescale.com, avorontsov@ru.mvista.com Hi, On Tue, Nov 22 2011, Tony Lin wrote: > 1ms is enough for hardware to change the clock to stable. > 100ms is too long in the tasklet. > > Signed-off-by: Tony Lin > CC: Xiaobo Xie > CC: Anton Vorontsov > --- > drivers/mmc/host/sdhci-esdhc.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h > index c3b08f1..b97b2f5 100644 > --- a/drivers/mmc/host/sdhci-esdhc.h > +++ b/drivers/mmc/host/sdhci-esdhc.h > @@ -73,7 +73,7 @@ static inline void esdhc_set_clock(struct sdhci_host > *host, unsigned int clock) > | (div << ESDHC_DIVIDER_SHIFT) > | (pre_div << ESDHC_PREDIV_SHIFT)); > sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL); > - mdelay(100); > + mdelay(1); > out: > host->clock = clock; > } I don't know if 1ms is actually long enough for the clock to stabilize on all boards, but I'll push this change to mmc-next and we can see if we get any regression reports. Thanks, - Chris. -- Chris Ball One Laptop Per Child