From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754809AbdAEHYL (ORCPT ); Thu, 5 Jan 2017 02:24:11 -0500 Received: from regular1.263xmail.com ([211.150.99.139]:44367 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267AbdAEHXx (ORCPT ); Thu, 5 Jan 2017 02:23:53 -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: ulf.hansson@linaro.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: xzy.xu@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: Ziyuan Xu To: ulf.hansson@linaro.org, jh80.chung@samsung.com, shawn.lin@rock-chips.com Cc: linux-mmc@vger.kernel.org, randy.li@rock-chips.com, linux-rockchip@lists.infradead.org, Ziyuan Xu , linux-kernel@vger.kernel.org Subject: [PATCH v4] mmc: dw_mmc: force setup bus if active slots exist Date: Thu, 5 Jan 2017 15:23:32 +0800 Message-Id: <1483601012-18241-1-git-send-email-xzy.xu@rock-chips.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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); } /* Now that slots are all setup, we can enable card detect */ -- 2.7.4