From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [RFC][PATCH] PM / Domains: Return -EPROBE_DEFER if we fail to init or turn-on domain Date: Fri, 24 Jul 2015 14:12:38 +0100 Message-ID: <55B239C6.2010003@nvidia.com> References: <1434649967-21135-1-git-send-email-jonathanh@nvidia.com> <55A3B7E0.8040401@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from hqemgate15.nvidia.com ([216.228.121.64]:12537 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753389AbbGXNMo (ORCPT ); Fri, 24 Jul 2015 09:12:44 -0400 In-Reply-To: <55A3B7E0.8040401@nvidia.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Ulf Hansson , "Rafael J. Wysocki" , Kevin Hilman Cc: "linux-pm@vger.kernel.org" On 13/07/15 14:06, Jon Hunter wrote: > > On 24/06/15 11:18, Ulf Hansson wrote: >> On 18 June 2015 at 19:52, Jon Hunter wrote: >>> When a device is probed, the function dev_pm_domain_attach() is called >>> to see if there is a power-domain that is associated with the device and >>> needs to be turned on. If dev_pm_domain_attach() does not return >>> -EPROBE_DEFER then the device will be probed. >>> >>> For devices using genpd, dev_pm_domain_attach() will call >>> genpd_dev_pm_attach(). If genpd_dev_pm_attach() does not find a power >>> domain associated with the device then it returns an error code not >>> equal to -EPROBE_DEFER to allow the device to be probed. However, if >>> genpd_dev_pm_attach() does find a power-domain that is associated with >>> the device, then it does not return -EPROBE_DEFER on failure and hence >>> the device will still be probed. Furthermore, genpd_dev_pm_attach() does >>> not check the error code returned by pm_genpd_poweron() to see if the >>> power-domain was turned on successfully. >>> >>> Signed-off-by: Jon Hunter >> >> This is a clear improvement for genpd and as a short-term solution I >> am fine with this! >> >> The long term solution should be to implement the >> pm_domain->activate|dismiss() callbacks, but that requires a bigger >> effort. >> >> Acked-by: Ulf Hansson > > Thanks Ulf. > > Kevin, Rafael, are you ok with this? I have still not heard back about this. Ulf, not sure if you can help here. Cheers Jon ----------------------------------------------------------------------------------- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. -----------------------------------------------------------------------------------