From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: Issues with GPIO and wake from sleep Date: Thu, 13 Feb 2014 14:40:49 -0800 Message-ID: <20140213224048.GA28216@atomide.com> References: <20140117173902.GD7235@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:52573 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751854AbaBMWlB (ORCPT ); Thu, 13 Feb 2014 17:41:01 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Marc Murphy Cc: "linux-omap@vger.kernel.org" * Marc Murphy [140205 15:20]: > I have now stepped through most of the system as it goes into the sleep state. It will transition into omap34xx_cpu_suspend and eventually work itself into an endless loop. > > I have then taken a step back to see the config of the system and all kernel options seem to be correct with power management. > > I then looked at the boot line, I am running tftp which should be a problem for the suspend to ram, and there is an option of nohlt : > setenv bootargs console=${console},115200n8 ${mem_size} mpurate=${mpurate} ${video_mode} ${extra_options} root=${nfsroot} rootfstype=nfs ip=dhcp nohlt rw > > I was informed I needed to do this quite some time ago when I was having issue with the system booting. Upon reading the kernel-paramters doc I see that the description is what I am experiencing; > nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or > wfi(ARM) instruction doesn't work correctly and not to > use it. This is also useful when using JTAG debugger. > > OK so WFI doesn't work correctly, I have no WFI operating. If I remove the nohlt from the boot line the system freezes; > [ 2.833587] voltdm_scale: No voltage scale API registered for vdd_core > [ 2.840454] PM: no software I/O chain control; some wakeups may be lost > [ 2.856536] davinci_emac davinci_emac.0: using random MAC addr: 86:2d:4d:a4:87:3e It seems that this is a 3517 based issue, maybe the davinci_emac driver won't work properly with runtime PM? Tony