ath5k: disable ASPM L0s for all cards

[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / net / wireless / ath / ath5k / base.c

diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index 0d5de25..373dcfe 100644 (file)
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -48,6 +48,7 @@
 #include <linux/netdevice.h>
 #include <linux/cache.h>
 #include <linux/pci.h>
+#include <linux/pci-aspm.h>
 #include <linux/ethtool.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
@@ -476,6 +477,26 @@ ath5k_pci_probe(struct pci_dev *pdev,
        int ret;
        u8 csz;
 
+       /*
+        * L0s needs to be disabled on all ath5k cards.
+        *
+        * For distributions shipping with CONFIG_PCIEASPM (this will be enabled
+        * by default in the future in 2.6.36) this will also mean both L1 and
+        * L0s will be disabled when a pre 1.1 PCIe device is detected. We do
+        * know L1 works correctly even for all ath5k pre 1.1 PCIe devices
+        * though but cannot currently undue the effect of a blacklist, for
+        * details you can read pcie_aspm_sanity_check() and see how it adjusts
+        * the device link capability.
+        *
+        * It may be possible in the future to implement some PCI API to allow
+        * drivers to override blacklists for pre 1.1 PCIe but for now it is
+        * best to accept that both L0s and L1 will be disabled completely for
+        * distributions shipping with CONFIG_PCIEASPM rather than having this
+        * issue present. Motivation for adding this new API will be to help
+        * with power consumption for some of these devices.
+        */
+       pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);
+
        ret = pci_enable_device(pdev);
        if (ret) {
                dev_err(&pdev->dev, "can't enable device\n");