From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Lin Subject: Re: [PATCH] mmc: Add a restriction to mmc debugfs clock setting. Date: Tue, 19 Jan 2016 15:44:19 +0800 Message-ID: <569DE953.6080605@rock-chips.com> References: <1453183995-46099-1-git-send-email-pawelx.wodkowski@intel.com> <569DD931.6050001@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from lucky1.263xmail.com ([211.157.147.133]:54210 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752267AbcASHol (ORCPT ); Tue, 19 Jan 2016 02:44:41 -0500 In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: "Wodkowski, PawelX" , "linux-mmc@vger.kernel.org" Cc: shawn.lin@rock-chips.com, "Dong, Chuanxiao" , "Yuan, Juntao" On 2016/1/19 14:44, Wodkowski, PawelX wrote: >> -----Original Message----- >> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc- >> owner@vger.kernel.org] On Behalf Of Shawn Lin >> Sent: Tuesday, January 19, 2016 7:35 AM >> To: Wodkowski, PawelX ; linux- >> mmc@vger.kernel.org >> Cc: shawn.lin@rock-chips.com; Dong, Chuanxiao >> ; Yuan, Juntao >> Subject: Re: [PATCH] mmc: Add a restriction to mmc debugfs clock setting. >> >> On 2016/1/19 14:13, Pawel Wodkowski wrote: >>> From: Chuanxiao Dong >>> >>> Clock frequency values written to an mmc host should not be less than >>> the minimum clock frequency which the mmc host supports. >>> >>> Signed-off-by: Yuan Juntao >>> Signed-off-by: Pawel Wodkowski >>> --- >>> drivers/mmc/core/debugfs.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c >>> index 154aced0b91b..bdfce774d848 100644 >>> --- a/drivers/mmc/core/debugfs.c >>> +++ b/drivers/mmc/core/debugfs.c >>> @@ -220,7 +220,7 @@ static int mmc_clock_opt_set(void *data, u64 >> val) >>> struct mmc_host *host = data; >>> >>> /* We need this check due to input value is u64 */ >>> - if (val > host->f_max) >>> + if (val > host->f_max || val < host->f_min) >> >> Hmm... how about if I want to disable clk from sysfs and pass ZERO to >> mmc_clock_opt_set, doesn't that case make sense? :) >> > > So maybe something like this? > if (val != 0 && (val > host->f_max || val < host->f_min)) yep. > -- Best Regards Shawn Lin