From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44470 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965391AbeCGTqI (ORCPT ); Wed, 7 Mar 2018 14:46:08 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shawn Lin , Jaehoon Chung , Ulf Hansson Subject: [PATCH 4.14 017/110] mmc: dw_mmc: Avoid accessing registers in runtime suspended state Date: Wed, 7 Mar 2018 11:38:00 -0800 Message-Id: <20180307191041.932087686@linuxfoundation.org> In-Reply-To: <20180307191039.748351103@linuxfoundation.org> References: <20180307191039.748351103@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shawn Lin commit 5b43df8b4c1a7f0c3fbf793c9566068e6b1e570c upstream. cat /sys/kernel/debug/mmc0/regs will hang up the system since it's in runtime suspended state, so the genpd and biu_clk is off. This patch fixes this problem by calling pm_runtime_get_sync to wake it up before reading the registers. Fixes: e9ed8835e990 ("mmc: dw_mmc: add runtime PM callback") Cc: Signed-off-by: Shawn Lin Reviewed-by: Jaehoon Chung Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/host/dw_mmc.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -165,6 +165,8 @@ static int dw_mci_regs_show(struct seq_f { struct dw_mci *host = s->private; + pm_runtime_get_sync(host->dev); + seq_printf(s, "STATUS:\t0x%08x\n", mci_readl(host, STATUS)); seq_printf(s, "RINTSTS:\t0x%08x\n", mci_readl(host, RINTSTS)); seq_printf(s, "CMD:\t0x%08x\n", mci_readl(host, CMD)); @@ -172,6 +174,8 @@ static int dw_mci_regs_show(struct seq_f seq_printf(s, "INTMASK:\t0x%08x\n", mci_readl(host, INTMASK)); seq_printf(s, "CLKENA:\t0x%08x\n", mci_readl(host, CLKENA)); + pm_runtime_put_autosuspend(host->dev); + return 0; }