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authorMatthew Garrett <mjg@redhat.com>2010-06-09 16:05:07 -0400
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-07-30 09:29:15 -0700
commit41cd766b065970ff6f6c89dd1cf55fa706c84a3d (patch)
treef52a7346daaaad331dbd260f0e21bcf9d108b2e6 /drivers/pci
parent4302e0fb7fa5b071e30f3cfb68e85155b3d69d9b (diff)
PCI: Don't enable aspm before drivers have had a chance to veto it
The aspm code will currently set the configured aspm policy before drivers have had an opportunity to indicate that their hardware doesn't support it. Unfortunately, putting some hardware in L0 or L1 can result in the hardware no longer responding to any requests, even after aspm is disabled. It makes more sense to leave aspm policy at the BIOS defaults at initial setup time, reconfiguring it after pci_enable_device() is called. This allows the driver to blacklist individual devices beforehand. Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pcie/aspm.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index be53d98fa384..71222814c1ec 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -588,11 +588,23 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
* update through pcie_aspm_cap_init().
*/
pcie_aspm_cap_init(link, blacklist);
- pcie_config_aspm_path(link);
/* Setup initial Clock PM state */
pcie_clkpm_cap_init(link, blacklist);
- pcie_set_clkpm(link, policy_to_clkpm_state(link));
+
+ /*
+ * At this stage drivers haven't had an opportunity to change the
+ * link policy setting. Enabling ASPM on broken hardware can cripple
+ * it even before the driver has had a chance to disable ASPM, so
+ * default to a safe level right now. If we're enabling ASPM beyond
+ * the BIOS's expectation, we'll do so once pci_enable_device() is
+ * called.
+ */
+ if (aspm_policy != POLICY_POWERSAVE) {
+ pcie_config_aspm_path(link);
+ pcie_set_clkpm(link, policy_to_clkpm_state(link));
+ }
+
unlock:
mutex_unlock(&aspm_lock);
out: