From 57d86a0485a30145382ad03b9504cc03ba4641c7 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 19 Nov 2015 08:05:35 -0800 Subject: PCI/ASPM: Make sysfs link_state_store() consistent with link_state_show() If CONFIG_PCIEASPM_DEBUG is set, then PCI devices have a link_state attribute. Reading that attribute shows the state as a bit mask: 1 means L0S upstream, 2 means L0S downstream, and 4 means L1. Oddly, writing to link_state is inconsistent and gets translated, leading to mysterious results in which the value you store isn't comparable the value you load back out. Fix it by making link_state_store() match link_state_show(). [bhelgaas: Check "aspm_disabled" *before* validating input. When "aspm_disabled" is set, this changes the error for invalid input from -EINVAL to -EPERM.] Signed-off-by: Andy Lutomirski Signed-off-by: Bjorn Helgaas --- drivers/pci/pcie/aspm.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) (limited to 'drivers/pci/pcie/aspm.c') diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 317e3558a35e..2dfe7fdb77e7 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -834,21 +834,15 @@ static ssize_t link_state_store(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); struct pcie_link_state *link, *root = pdev->link_state->root; - u32 val, state = 0; - - if (kstrtouint(buf, 10, &val)) - return -EINVAL; + u32 state; if (aspm_disabled) return -EPERM; - if (n < 1 || val > 3) - return -EINVAL; - /* Convert requested state to ASPM state */ - if (val & PCIE_LINK_STATE_L0S) - state |= ASPM_STATE_L0S; - if (val & PCIE_LINK_STATE_L1) - state |= ASPM_STATE_L1; + if (kstrtouint(buf, 10, &state)) + return -EINVAL; + if ((state & ~ASPM_STATE_ALL) != 0) + return -EINVAL; down_read(&pci_bus_sem); mutex_lock(&aspm_lock); -- cgit