Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753745Ab1CGPCP (ORCPT ); Mon, 7 Mar 2011 10:02:15 -0500 Received: from smtp.eu.citrix.com ([62.200.22.115]:23160 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752506Ab1CGPCO (ORCPT ); Mon, 7 Mar 2011 10:02:14 -0500 X-IronPort-AV: E=Sophos;i="4.62,277,1297036800"; d="scan'208";a="4652616" Date: Mon, 7 Mar 2011 15:01:56 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball-desktop To: Jesse Barnes CC: Stefano Stabellini , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , "linux-pci@vger.kernel.org" , Allen Kay Subject: Re: [RFC PATCH] set current_state to D0 in register_slot In-Reply-To: <20110304104251.45b257c4@jbarnes-desktop> Message-ID: References: <20110304104251.45b257c4@jbarnes-desktop> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2139 Lines: 58 On Fri, 4 Mar 2011, Jesse Barnes wrote: > On Mon, 28 Feb 2011 16:20:11 +0000 > Stefano Stabellini wrote: > > > Hi all, > > if a device doesn't support power management (pm_cap == 0) but it is > > acpi_pci_power_manageable() because there is a _PS0 method declared for > > it and _EJ0 is also declared for the slot then nobody is going to set > > current_state = PCI_D0 for this device. This is what I think it is > > happening: > > > > > > pci_enable_device > > | > > __pci_enable_device_flags > > /* here we do not set current_state because !pm_cap */ > > | > > do_pci_enable_device > > | > > pci_set_power_state > > | > > __pci_start_power_transition > > | > > pci_platform_power_transition > > /* platform_pci_power_manageable() calls acpi_pci_power_manageable that > > * returns true */ > > | > > platform_pci_set_power_state > > /* acpi_pci_set_power_state gets called and does nothing because the > > * acpi device has _EJ0, see the comment "If the ACPI device has _EJ0, > > * ignore the device" */ > > > > > > at this point if we refer to the commit message that introduced the > > comment above (10b3dcae0f275e2546e55303d64ddbb58cec7599), it is up to > > the hotplug driver to set the state to D0. > > However AFAICT the pci hotplug driver never does, in fact > > drivers/pci/hotplug/acpiphp_glue.c:register_slot sets the slot flags to > > (SLOT_ENABLED | SLOT_POWEREDON) but it does not set the pci device > > current state to PCI_D0. > > > > So my proposed fix is also to set current_state = PCI_D0 in > > register_slot. > > Comments are very welcome. > > > > > > Signed-off-by: Stefano Stabellini > > Yeah, looks fine. ACPIPHP is happy for the attention. :) Great, thanks! Would you be OK with taking this patch in your tree? Or do you prefer me to send to it Linus myself? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/