Re: [PATCH] ath5k: disable ASPM

["Luis R. Rodriguez" <mcgrof@gmail.com>]

On Fri, May 28, 2010 at 3:09 AM, Jussi Kivilinna
<jussi.kivilinna@mbnet.fi> wrote:
> Atheros card on Acer Aspire One (AOA150, Atheros Communications Inc. AR5001
> Wireless Network Adapter [168c:001c] (rev 01)) doesn't work well with ASPM
> enabled. With ASPM ath5k will eventually stall on heavy traffic with often
> 'unsupported jumbo' warnings appearing. Disabling ASPM L0s/L1 in ath5k fixes
> these problems.

So you disable ASPM all together on the entire driver?

  Luis

> Reproduced with pcie_aspm=force and by using 'nc < /dev/zero > /dev/null' at
> both ends (usually stalls within seconds).
>
> Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
> ---
>  drivers/net/wireless/ath/ath5k/base.c |   48 +++++++++++++++++++++++++++++++++
>  1 files changed, 48 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
> index cc6d41d..ce9c983 100644
> --- 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>
> @@ -195,6 +196,8 @@ static const struct ieee80211_rate ath5k_rates[] = {
>  static int __devinit   ath5k_pci_probe(struct pci_dev *pdev,
>                                const struct pci_device_id *id);
>  static void __devexit  ath5k_pci_remove(struct pci_dev *pdev);
> +static void            __ath5k_disable_aspm(struct pci_dev *pdev, u16 state);
> +static void            ath5k_disable_aspm(struct pci_dev *pdev, u16 state);
>  #ifdef CONFIG_PM
>  static int             ath5k_pci_suspend(struct device *dev);
>  static int             ath5k_pci_resume(struct device *dev);
> @@ -424,6 +427,47 @@ module_exit(exit_ath5k_pci);
>  * PCI Initialization *
>  \********************/
>
> +#ifdef CONFIG_PCIEASPM
> +static void __ath5k_disable_aspm(struct pci_dev *pdev, u16 state)
> +{
> +       pci_disable_link_state(pdev, state);
> +}
> +#else
> +static void __ath5k_disable_aspm(struct pci_dev *pdev, u16 state)
> +{
> +       int pos;
> +       u16 reg16;
> +
> +       /*
> +        * Both device and parent should have the same ASPM setting.
> +        * Disable ASPM in downstream component first and then upstream.
> +        */
> +       pos = pci_pcie_cap(pdev);
> +       pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, &reg16);
> +       reg16 &= ~state;
> +       pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16);
> +
> +       if (!pdev->bus->self)
> +               return;
> +
> +       pos = pci_pcie_cap(pdev->bus->self);
> +       pci_read_config_word(pdev->bus->self, pos + PCI_EXP_LNKCTL, &reg16);
> +       reg16 &= ~state;
> +       pci_write_config_word(pdev->bus->self, pos + PCI_EXP_LNKCTL, reg16);
> +}
> +#endif
> +static void ath5k_disable_aspm(struct pci_dev *pdev, u16 state)
> +{
> +       if (!pdev->is_pcie)
> +               return;
> +
> +       dev_info(&pdev->dev, "Disabling ASPM %s%s\n",
> +                (state & PCIE_LINK_STATE_L0S) ? "L0s " : "",
> +                (state & PCIE_LINK_STATE_L1) ? "L1" : "");
> +
> +       __ath5k_disable_aspm(pdev, state);
> +}
> +
>  static const char *
>  ath5k_chip_name(enum ath5k_srev_type type, u_int16_t val)
>  {
> @@ -473,6 +517,8 @@ ath5k_pci_probe(struct pci_dev *pdev,
>        int ret;
>        u8 csz;
>
> +       ath5k_disable_aspm(pdev, PCIE_LINK_STATE_L1 | PCIE_LINK_STATE_L0S);
> +
>        ret = pci_enable_device(pdev);
>        if (ret) {
>                dev_err(&pdev->dev, "can't enable device\n");
> @@ -725,6 +771,8 @@ static int ath5k_pci_resume(struct device *dev)
>        struct ieee80211_hw *hw = pci_get_drvdata(pdev);
>        struct ath5k_softc *sc = hw->priv;
>
> +       ath5k_disable_aspm(pdev, PCIE_LINK_STATE_L1 | PCIE_LINK_STATE_L0S);
> +
>        /*
>         * Suspend/Resume resets the PCI configuration space, so we have to
>         * re-disable the RETRY_TIMEOUT register (0x41) to keep
>
> --
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