From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761233AbdAIGlM (ORCPT ); Mon, 9 Jan 2017 01:41:12 -0500 Received: from lucky1.263xmail.com ([211.157.147.133]:37562 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753533AbdAIGlD (ORCPT ); Mon, 9 Jan 2017 01:41:03 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 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 v4] mmc: dw_mmc: force setup bus if active slots exist To: Jaehoon Chung , Ziyuan , ulf.hansson@linaro.org References: <1483601012-18241-1-git-send-email-xzy.xu@rock-chips.com> <49544a65-9b3c-c56a-e5f7-89c5fa6e6cd0@rock-chips.com> <587305E5.30003@rock-chips.com> <7c41a01e-ded2-9c03-78d9-c0b75984bf20@samsung.com> Cc: shawn.lin@rock-chips.com, randy.li@rock-chips.com, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org From: Shawn Lin Message-ID: Date: Mon, 9 Jan 2017 14:40:10 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <7c41a01e-ded2-9c03-78d9-c0b75984bf20@samsung.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/1/9 13:41, Jaehoon Chung wrote: > On 01/09/2017 12:39 PM, Ziyuan wrote: >> >> >> On 01/05/2017 03:34 PM, Shawn Lin wrote: >>> On 2017/1/5 15:23, Ziyuan Xu wrote: >>>> It's necessary to setup bus if any slots are present. >>>> - update clock after ctrl reset >>>> - if the host has genpd node, we can guarantee the clock is available >>>> before starting request. Otherwies, the clock register is reset once >>>> power off the pd, and host can't output the active clock during >>>> communication. >>>> >>>> fixes: e9ed8835e990 ("mmc: dw_mmc: add runtime PM callback") >>>> Reported-by: Randy Li >>>> Signed-off-by: Ziyuan Xu >>>> >>>> --- >>>> Hi guys, >>>> >>>> I found a similar issue on rk3399 platform, which has a genpd node for >>>> SD card host. Power off-on pd will reset the registers to a default >>>> value (ie. CLKENA), so that the host can't output the active clock >>>> during communication. >>>> >>> >>> Indeed, Caesar recently introduced all the genpd for rk3399 platform, >>> so we need to restore them. >>> >>>> So we need to setup bus in rpm resume. It also wraps the update clock >>>> behaviour which I did in V3. >>>> >>>> Thanks, >>>> Ziyuan Xu >>>> >>>> >>>> Changes in v4: >>>> - update commit message >>>> - fix SD host rpm resume can't work >>>> >>>> Changes in v3: >>>> - only reset host with active slot. >>>> >>>> Changes in v2: >>>> - update the commit message >>>> - use dw_mci_reset instead of dw_mci_ctrl_reset >>>> >>>> drivers/mmc/host/dw_mmc.c | 6 +++--- >>>> 1 file changed, 3 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >>>> index b44306b..b6053b3 100644 >>>> --- a/drivers/mmc/host/dw_mmc.c >>>> +++ b/drivers/mmc/host/dw_mmc.c >>>> @@ -3354,10 +3354,10 @@ int dw_mci_runtime_resume(struct device *dev) >>>> >>>> if (!slot) >>>> continue; >>>> - if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) { >>>> + if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) >>>> dw_mci_set_ios(slot->mmc, &slot->mmc->ios); >>>> - dw_mci_setup_bus(slot, true); >>>> - } >>>> + /* Force setup bus to guarantee available clock output */ >>>> + dw_mci_setup_bus(slot, true); >>> >>> So the spamming message about >>> >>> "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n" >>> >>> will always be there, right? So you could append a new patch to shut >>> up it as I think it's useless no matter for system pm or rpm to print >>> it. How about? >> >> Fine, it's favourable with dev_vdbg if the dw_mmc rpm is enabled. >> Hi Jaehoon, >> What's your opinion? If you think this patch and shawn's advice are acceptable, I will send the v5 patch. > > I don't agreed to use dev_vdbg()..but it needs not to display at everytime. > Hmm..It needs to consider more..because we needs to see the clock value when it's initialized. > A very stright-forward way is to pass a flag to shut up the spamming log when it's called from the PM context? > Best Regards, > Jaehoon Chung > >> >> BR >> Ziyuan Xu >> >>> >>>> } >>>> >>>> /* Now that slots are all setup, we can enable card detect */ >>>> >>> >>> >> >> >> >> >> > > > > -- Best Regards Shawn Lin