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authorAndy Lutomirski <luto@kernel.org>2015-11-19 19:05:35 +0300
committerBjorn Helgaas <bhelgaas@google.com>2015-12-03 19:42:59 +0300
commit57d86a0485a30145382ad03b9504cc03ba4641c7 (patch)
tree25e13c900e23fe6a7bdd67dd29946c5af0763f94 /drivers/pci/pcie
parent1ec218373b8ebda821aec00bb156a9c94fad9cd4 (diff)
downloadlinux-57d86a0485a30145382ad03b9504cc03ba4641c7.tar.xz
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 <luto@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pcie')
-rw-r--r--drivers/pci/pcie/aspm.c16
1 files changed, 5 insertions, 11 deletions
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);