On Wed, 22 Nov 2017, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote:
> On 11/22/2017 2:52 AM, Joonas Lahtinen wrote:
>> Dropping the extra mailing lists and Dave, this is a rather trivial thing.
>>
>> On Wed, 2017-11-22 at 00:30 -0500, Sinan Kaya wrote:
>>> pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
>>> where a PCI device is present. This restricts the device drivers to be
>>> reused for other domain numbers.
>>>
>>> Use pci_get_domain_bus_and_slot() with a domain number of 0 where we can't
>>> extract the domain number. Other places, use the actual domain number from
>>> the device.
>>>
>>> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
>>
>> <SNIP>
>>
>>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>>> @@ -419,7 +419,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
>>>
>>> static int i915_get_bridge_dev(struct drm_i915_private *dev_priv)
>>> {
>>> - dev_priv->bridge_dev = pci_get_bus_and_slot(0, PCI_DEVFN(0, 0));
>>> + uint16_t devfn = PCI_DEVFN(0, 0)
>>
>> The would have to be "unsigned int" according to the function
>> signature.
>
> Even though the return value is unsigned int, PCI_DEVFN cannot be bigger
> than 16 bits.
>
> http://elixir.free-electrons.com/linux/v4.14.1/source/include/uapi/linux/pci.h#L31
>
> /*
> * The PCI interface treats multi-function devices as independent
> * devices. The slot/function address of each device is encoded
> * in a single byte as follows:
> *
> * 7:3 = slot
> * 2:0 = function
> */
>
> It is common practice to use u16 for keeping devfn information in the
> kernel.
>
>>
>>> +
>>> + dev_priv->bridge_dev = pci_get_domain_bus_and_slot(0, 0, devfn);
>>
>> But the most straightforward change is to simply convert to:
>>
>> dev_priv->bridge_dev = pci_get_domain_bus_and_slot(0, 0,
>> PCI_DEVFN(0, 0));
>>
>> Can you please resend like that.
>
> I did this at the beginning and but, I hit a checkpatch problem with
> more than 80 characters. That's why, I moved the devfn value assignment
> to a different line.
Please ignore checkpatch when it makes the code worse. 80 is not a
strict limit.
BR,
Jani.
>
>>
>> Looks like this is a part of abigger series, so others may prefer
>> latter form too, to avoid the variable.
>>
>> Regards, Joonas
>>
--
Jani Nikula, Intel Open Source Technology Center
