diff options
author | Andy Lutomirski <luto@kernel.org> | 2015-11-19 19:05:35 +0300 |
---|---|---|
committer | Bjorn Helgaas <bhelgaas@google.com> | 2015-12-03 19:42:59 +0300 |
commit | 57d86a0485a30145382ad03b9504cc03ba4641c7 (patch) | |
tree | 25e13c900e23fe6a7bdd67dd29946c5af0763f94 /drivers/pci/pcie | |
parent | 1ec218373b8ebda821aec00bb156a9c94fad9cd4 (diff) | |
download | linux-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.c | 16 |
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); |