From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756661AbcEDBtO (ORCPT ); Tue, 3 May 2016 21:49:14 -0400 Received: from lucky1.263xmail.com ([211.157.147.133]:45361 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756112AbcEDBtM (ORCPT ); Tue, 3 May 2016 21:49:12 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-KSVirus-check: 0 X-RL-SENDER: shawn.lin@rock-chips.com X-FST-TO: linux-rockchip@lists.infradead.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: shawn.lin@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH v2] mmc: sdhci-of-arasan: fix set_clock when a phy is supported To: Ulf Hansson References: <1461832731-28422-1-git-send-email-shawn.lin@rock-chips.com> Cc: shawn.lin@rock-chips.com, Adrian Hunter , Michal Simek , =?UTF-8?Q?S=c3=b6ren_Brinkmann?= , linux-mmc , "linux-kernel@vger.kernel.org" , Doug Anderson , Heiko Stuebner , "open list:ARM/Rockchip SoC..." From: Shawn Lin Message-ID: <1d3a9de8-9092-add5-078e-66ce4ce5f6f3@rock-chips.com> Date: Wed, 4 May 2016 09:48:55 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2016/4/28 18:38, Ulf Hansson 写道: > On 28 April 2016 at 10:38, Shawn Lin wrote: >> commit 61b914eb81f8 ("mmc: sdhci-of-arasan: add phy support for >> sdhci-of-arasan") introduce phy support for arasan. According to >> the vendor's databook, we should make sure the phy is in poweroff >> status before we configure the clk stuff. Otherwise it may cause >> some IO sample timing issues from the test. And we don't need this >> extra operation while running in low performance mode since phy >> doesn't trigger sampling block. >> >> Signed-off-by: Shawn Lin > > Thanks, applied for next! Thanks for applying v2 but, could you please drop it and applied v3 I just send :) . Because v2 introduces a bug. Set_clock callback will be called under the protection of spinlock in sdhci_do_set_ios. However PHY APIs need mutex which fails the kernel's debug check BUG: sleeping function called from invalid context at kernel/locking/mutex.c > > Kind regards > Uffe > >> >> --- >> >> Changes in v2: >> - change commit msg title to indicate it's a fix >> - fix a typo in commmit msg >> >> drivers/mmc/host/sdhci-of-arasan.c | 20 +++++++++++++++++++- >> 1 file changed, 19 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c >> index 2e482b1..20b859e 100644 >> --- a/drivers/mmc/host/sdhci-of-arasan.c >> +++ b/drivers/mmc/host/sdhci-of-arasan.c >> @@ -55,8 +55,26 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host) >> return freq; >> } >> >> +static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) >> +{ >> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> + struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); >> + bool ctrl_phy = false; >> + >> + if (clock > MMC_HIGH_52_MAX_DTR && (!IS_ERR(sdhci_arasan->phy))) >> + ctrl_phy = true; >> + >> + if (ctrl_phy) >> + phy_power_off(sdhci_arasan->phy); >> + >> + sdhci_set_clock(host, clock); >> + >> + if (ctrl_phy) >> + phy_power_on(sdhci_arasan->phy); >> +} >> + >> static struct sdhci_ops sdhci_arasan_ops = { >> - .set_clock = sdhci_set_clock, >> + .set_clock = sdhci_arasan_set_clock, >> .get_max_clock = sdhci_pltfm_clk_get_max_clock, >> .get_timeout_clock = sdhci_arasan_get_timeout_clock, >> .set_bus_width = sdhci_set_bus_width, >> -- >> 2.3.7 >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- Best Regards Shawn Lin