Failed to wake device (9984)

[Adrian Chadd]

On 15 September 2017 at 13:19, Ben Greear <greearb at candelatech.com> wrote:

> It is not that reliable.  I'm now trying a hack to re-probe the bus up
> to 3 times if we fail....hoping maybe that will help.
>
> We just hit a case where the first 2 times failed, but it booted on
> the third.

See if there's a call to reset and reprobe/re-BAR the PCI resources
that you can do from inside of linux kernel code.



-adrian

> My patch looks like this:
>
> diff --git a/drivers/net/wireless/ath/ath10k/pci.c
> b/drivers/net/wireless/ath/ath10k/pci.c
> index e0a7b338..711b3f0 100644
> --- a/drivers/net/wireless/ath/ath10k/pci.c
> +++ b/drivers/net/wireless/ath/ath10k/pci.c
> @@ -3492,8 +3492,8 @@ static const struct ath10k_bus_ops ath10k_pci_bus_ops
> = {
>         .get_num_banks  = ath10k_pci_get_num_banks,
>  };
>
> -static int ath10k_pci_probe(struct pci_dev *pdev,
> -                           const struct pci_device_id *pci_dev)
> +static int __ath10k_pci_probe(struct pci_dev *pdev,
> +                             const struct pci_device_id *pci_dev)
>  {
>         int ret = 0;
>         struct ath10k *ar;
> @@ -3668,6 +3668,22 @@ static int ath10k_pci_probe(struct pci_dev *pdev,
>         return ret;
>  }
>
> +static int ath10k_pci_probe(struct pci_dev *pdev,
> +                           const struct pci_device_id *pci_dev)
> +{
> +       int cnt = 0;
> +       int rv;
> +       do {
> +               rv = __ath10k_pci_probe(pdev, pci_dev);
> +               if (rv == 0)
> +                       return rv;
> +               pr_err("ath10k: failed to probe PCI : %d, retry-count:
> %d\n", rv, cnt);
> +               udelay(10000); /* let the ath10k firmware gerbil take a
> small break */
> +       } while (cnt++ < 3);
> +       return rv;
> +}
> +
> +
>  static void ath10k_pci_remove(struct pci_dev *pdev)
>  {
>         struct ath10k *ar = pci_get_drvdata(pdev);
>
>
> Thanks,
> Ben
>
>
>>
>>> We'll see if that is a reliable way to recover from this problem.  And,
>>> will
>>> see if we
>>> can also find a nicer way to go about it...maybe there is just a timer
>>> that
>>> is not long
>>> enough somewhere?
>>
>>
>> It's possible. I am just always wary about their host glue in the chip
>> :-) If reloading the driver helps then great. But all that /should/ be
>> dong is a cold reset / wakeup..
>>
>>
>>
>> -adrian
>>
>> _______________________________________________
>> ath10k mailing list
>> ath10k at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/ath10k
>>
>
>
> --
> Ben Greear <greearb at candelatech.com>
> Candela Technologies Inc  http://www.candelatech.com
>