From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [patch 2.6.14-rc1] pci: only call pci_restore_bars at boot Date: Wed, 14 Sep 2005 11:08:12 -0400 Message-ID: <43283CDC.3070603@pobox.com> References: <09142005095242.32027@bilbo.tuxdriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <09142005095242.32027@bilbo.tuxdriver.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: "John W. Linville" Cc: akpm@osdl.org, kaos@sgi.com, rmk+lkml@arm.linux.org.uk, grundler@parisc-linux.org, matthew@wil.cx, linux-pm@lists.osdl.org, linux-kernel@vger.kernel.org, torvalds@osdl.org, ink@jurassic.park.msu.ru, linux-pci@atrey.karlin.mff.cuni.cz, davem@davemloft.net List-Id: linux-pm@vger.kernel.org John W. Linville wrote: > Certain (SGI?) ia64 boxes object to having their PCI BARs > restored unless absolutely necessary. This patch restricts calling > pci_restore_bars from pci_set_power_state unless the current state > is PCI_UNKNOWN, the actual (i.e. physical) state of the device is > PCI_D3hot, and the device indicates that it will lose its configuration > when transitioning to PCI_D0. > > Signed-off-by: John W. Linville > --- > Many thanks to Keith Owens for a) narrowing-down the > problem; and, b) quickly testing the fix and reporting the results. > > drivers/pci/pci.c | 16 ++++++++++++---- > 1 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -309,17 +309,25 @@ pci_set_power_state(struct pci_dev *dev, > > pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); > > - /* If we're in D3, force entire word to 0. > + /* If we're (effectively) in D3, force entire word to 0. > * This doesn't affect PME_Status, disables PME_En, and > * sets PowerState to 0. > */ > - if (dev->current_state >= PCI_D3hot) { > - if (!(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) > + switch (dev->current_state) { > + case PCI_UNKNOWN: /* Boot-up */ > + if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot > + && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) > need_restore = 1; > + /* Fall-through: force to D0 */ > + case PCI_D3hot: > + case PCI_D3cold: > + case PCI_POWER_ERROR: > pmcsr = 0; > - } else { > + break; > + default: > pmcsr &= ~PCI_PM_CTRL_STATE_MASK; > pmcsr |= state; > + break; This seems like it will break a lot of stuff that -does- need the BARs restored when resuming from D3. Jeff