linux-kernel - Re: [PATCH] thunderbolt: Add support for INTEL_FALCON_RIDGE

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Message-ID: <CAMxnaaU1eMw5o9nJRmEgyw97oD25fRnjTcB_i+xAgc-V6m5HvA@mail.gmail.com>
Date:	Wed, 13 Jul 2016 00:17:33 +0200
From:	Andreas Noever <andreas.noever@...il.com>
To:	Lukas Wunner <lukas@...ner.de>
Cc:	Xavier Gnata <xavier.gnata@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>
Subject: Re: [PATCH] thunderbolt: Add support for INTEL_FALCON_RIDGE_2C controller

On Tue, Jul 12, 2016 at 11:13 PM, Lukas Wunner <lukas@...ner.de> wrote:
> On Tue, Jul 12, 2016 at 09:38:51PM +0200, Xavier Gnata wrote:
>> Add support to INTEL_FALCON_RIDGE_2C controller and corresponding quirk to
>> support suspend/resume.
>> Tested against 4.7 master on a MacBook Air 11" 2015
>
> Nice, thanks for doing this. See below for some comments.
>
>
>>
>> ---
>> drivers/thunderbolt/nhi.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
>> index 9c15344..b3d55ec 100644
>> --- a/drivers/thunderbolt/nhi.c
>> +++ b/drivers/thunderbolt/nhi.c
>> @@ -654,6 +654,12 @@ static struct pci_device_id nhi_ids[] = {
>> .device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI,
>> .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
>> },
>> + {
>> + .class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
>> + .vendor = PCI_VENDOR_ID_INTEL,
>> + .device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI,
>> + .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
>> + },
>> { 0,}
>> };
>>
>> --
>> 2.7.4
>>
>
> It looks like the indentation got mangled here, perhaps a Thunderbird
> issue or copy-pasta.
>
>
>>
>> ---
>>  drivers/pci/quirks.c | 23 +++++++++++++++--------
>>  1 file changed, 15 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index ee72ebe..e280351 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -3320,15 +3320,19 @@ static void quirk_apple_wait_for_thunderbolt(struct
>> pci_dev *dev)
>>         if (!sibling || !sibling->subordinate)
>>                 goto out;
>>         nhi = pci_get_slot(sibling->subordinate, 0x0);
>> -       if (!nhi)
>> -               goto out;
>> -       if (nhi->vendor != PCI_VENDOR_ID_INTEL
>> -                   || (nhi->device != PCI_DEVICE_ID_INTEL_LIGHT_RIDGE &&
>> -                       nhi->device != PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C
>> &&
>> -                       nhi->device !=
>> PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI)
>> -                   || nhi->subsystem_vendor != 0x2222
>> -                   || nhi->subsystem_device != 0x1111)
>> +       if (!nhi || nhi->vendor != PCI_VENDOR_ID_INTEL)
>>                 goto out;
>> +       if (nhi->device != PCI_DEVICE_ID_INTEL_LIGHT_RIDGE &&
>> +               nhi->device != PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C &&
>> +               nhi->device != PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI &&
>> +               nhi->device != PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI)
>> +        goto out;
>> +       if((nhi->device == PCI_DEVICE_ID_INTEL_LIGHT_RIDGE ||
>> +               nhi->device == PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C ||
>> +               nhi->device == PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI)
>> +               && (nhi->subsystem_vendor != 0x222
>                                                     ^
> You're missing a 2 here ----------------------------+
>
> The subsystem vendor/device should also not be checked on Falcon Ridge 4C,
> commit a42fb351ca1f ("thunderbolt: Allow loading of module on recent Apple
> MacBooks with thunderbolt 2 controller") removed that from the pci_device_id
> list but forgot to amend the quirk.

Yeah, we noticed that (off list). I was going to send a follow up
patch to fix that (just to keep the two things "Support FC_2C" and
"Fix suspend/resume for FC_4C" separate).

> Actually I'm wondering if we need to check the subsystem vendor/device id
> at all. If the motivation is to execute the quirk only for host controllers,
> this should probably be achieved by checking if the parent of the parent
> of the NHI has PCI_EXP_TYPE_ROOT_PORT set.
My idea was to check the device class - external thunderbolt devices
do not expose their controller through pci (even if they support
chaining). So all devices which match the device id and class should
be actual controllers.

Are thunderbolt controllers always installed directly below the root
port? In theory there could be more bridges in between (a candidate
for such a topology would be the mac pro which has 3 controllers).

Andreas
>
> Please also add PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI to tb_switch_alloc()
> so that the message "unsupported switch device id" is not printed for this
> controller.
>
> Thanks,
>
> Lukas
>
>> +               || nhi->subsystem_device != 0x1111))
>> +        goto out;
>>         dev_info(&dev->dev, "quirk: waiting for thunderbolt to reestablish
>> PCI tunnels...\n");
>>         device_pm_wait_for_dev(&dev->dev, &nhi->dev);
>>  out:
>> @@ -3344,6 +3348,9 @@ DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_INTEL,
>>  DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_INTEL,
>>                                PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_BRIDGE,
>>                                quirk_apple_wait_for_thunderbolt);
>> +DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_INTEL,
>> +                              PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_BRIDGE,
>> +                              quirk_apple_wait_for_thunderbolt);
>>  #endif
>>
>>  static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
>> --
>> 2.7.4