From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162686AbdAIDjb (ORCPT ); Sun, 8 Jan 2017 22:39:31 -0500 Received: from regular1.263xmail.com ([211.150.99.133]:50239 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933629AbdAIDjZ (ORCPT ); Sun, 8 Jan 2017 22:39:25 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: xzy.xu@rock-chips.com X-FST-TO: linux-rockchip@lists.infradead.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: xzy.xu@rock-chips.com X-UNIQUE-TAG: <3930b04e0b28026828598a4506c9c1ff> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH v4] mmc: dw_mmc: force setup bus if active slots exist To: Shawn Lin , ulf.hansson@linaro.org, jh80.chung@samsung.com References: <1483601012-18241-1-git-send-email-xzy.xu@rock-chips.com> <49544a65-9b3c-c56a-e5f7-89c5fa6e6cd0@rock-chips.com> Cc: randy.li@rock-chips.com, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org From: Ziyuan Message-ID: <587305E5.30003@rock-chips.com> Date: Mon, 9 Jan 2017 11:39:17 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <49544a65-9b3c-c56a-e5f7-89c5fa6e6cd0@rock-chips.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 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. BR Ziyuan Xu > >> } >> >> /* Now that slots are all setup, we can enable card detect */ >> > >