From patchwork Wed Sep 19 01:07:04 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: pci: don't touch card regs after runtime suspend D3 Date: Tue, 18 Sep 2012 15:07:04 -0000 From: Dave Airlie X-Patchwork-Id: 184898 Message-Id: <1348016824-1895-1-git-send-email-airlied@redhat.com> To: Bjorn Helgaas , linux-pci@vger.kernel.org If the driver takes care of state saving, don't touch any registers on it. Optimus (dual-gpu) laptops seem to have their own form of D3cold, but unfortunately enter it on normal D3 transitions via the ACPI callback. So when we use runtime PM to transition to D3, the card disappears off the PCI bus, however we then try to access registers on it in the runtime suspend finish, which really doesn't work. This patch check is the pci state is saved and doesn't attempt to hit any registers after that point if it is. (Looks okay to Rafael) Signed-off-by: Dave Airlie --- drivers/pci/pci-driver.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 5270f1a..214a40b 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1057,10 +1057,11 @@ static int pci_pm_runtime_suspend(struct device *dev) return 0; } - if (!pci_dev->state_saved) + if (!pci_dev->state_saved) { pci_save_state(pci_dev); - pci_finish_runtime_suspend(pci_dev); + pci_finish_runtime_suspend(pci_dev); + } return 0; }