From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELttH8TdM5/BcoDJJuHnug9S46s+JsR/n9Xbu6HQKRxHJ29h/4dA43PPDYcYCnDOS4NGV2jY ARC-Seal: i=1; a=rsa-sha256; t=1520451614; cv=none; d=google.com; s=arc-20160816; b=exwgR1G5uf4NjwCKZKH8ssL+L8oGrGUVj/Wewf8uej+PpWoqJ5Fo29ag2ov9ruPFRX /DgP/Up9lLOb/B4Fdpdtx1yv47qma560shv454IJ6kHcgVHmOm0nPx/CiEWbj6AwHlca i8uf74vGakLM+Z/hx+WxtCxKG5UucJTTnoveYA3LVqaqpCqmSz/jBJat3ndQr4CgGrNt i5y7xhXVMkpTQbYgPRB44OCX5K1m7hWDNCCejJIa8HEhD7WcLWTYuSEjhUy31WdXru5c KOBqvaWdiGEFxxi0MaSOZXeNIJYAvSdrswPw20UyGm/O09amWi6dFisz/XzlI/Nc8k8A mmJQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=NvZJdFsI1F+EUmOHqQFeeB9WRUniWIzbiju3NVFY+Nc=; b=HgjU40CJ2q9yb9OpQMrsXknHykmRhGQDfKjMQHS2AOkzY1NN78xrG4+ucbDdl8KfS7 bgKb5imlpSQONlFgtM9r1xUZZlkqAGeWRunIGo0M/fY8SfYiMlKZHGq3NSBKE9OQS4gK 7KvHYXRVn5EaX/mQCbrj2QXPTjkuzdP2TMUTnpHehFulE+VJ75+wSval2kwsXKpa/Ybu eQwoWUcOXVp2PChh3ieOaiOsVerTiavhoL3SJAYJYr9e1NyHPRHKeMOQD7ck9yrd9ae/ IlbVSWT7qwnRZjPq3SH3XaPWxBpDjzagtOU7kbmrj8e/FmM0XUhjwkJiZF9kENDdAOIv xeGA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org 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 4.15 020/122] mmc: dw_mmc: Avoid accessing registers in runtime suspended state Date: Wed, 7 Mar 2018 11:37:12 -0800 Message-Id: <20180307191732.271719877@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180307191729.190879024@linuxfoundation.org> References: <20180307191729.190879024@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1594309071701629543?= X-GMAIL-MSGID: =?utf-8?q?1594309071701629543?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-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; }