Re: [PATCH 0/3] Add SDHCI ACPI driver

Adrian Hunter
2012-11-23T10:10:46Z

On 23/11/12 11:34, Mika Westerberg wrote:
> On Thu, Nov 22, 2012 at 10:24:33PM +0100, Rafael J. Wysocki wrote:
>> On Thursday, November 22, 2012 04:46:10 PM Adrian Hunter wrote:
>>> On 22/11/12 15:55, Chris Ball wrote:
>>>> Hi,
>>>>
>>>> On Thu, Nov 22 2012, Adrian Hunter wrote:
>>>>> Here is SDHCI ACPI driver. It is dependent on new ACPI Platform support
>>>>> so I suggest Rafael takes the patches with Chris' Ack.
>>>>>
>>>>> Please note that I would prefer this to be queued for 3.8
>>>>
>>>> Looks fine:
>>>>
>>>> Acked-by: Chris Ball <cjb@laptop.org>
>>>
>>> Thank you!
>>>
>>>>
>>>> I have some dumb questions, though -- what kind of platforms ship with
>>>> these devices? Do they ever have the controller on PCI too, and what
>>>> happens with sdhci-pci vs. sdhci-acpi in that case?
>>>
>>> Since the arrival of ACPI5, platform devices can be configured using ACPI
>>> tables. PCI can also be used, but the firmware ensures that the same
>>> device is not enumerated via both ACPI and PCI.
>>>
>>> Rafael can you take these patches?
>>
>> Well, I'd prefer pnpacpi/core.c to actually use acpi_platform_device_ids[]
>> directly in addition to excluded_id_list[], so that duplicate entries don't
>> have to be added to the both of them.
>
> How about having pnpacpi to check if the ACPI device is already bound to a
> physical device and skip the device creation? Then we don't need to expose
> the acpi_platform_device_ids[] list, and this is what the ->find_device()
> code already does so why create the device in the first place?

Yes, I was going to suggest that too. AFAICS pnpacpi has no concept of
multiple physical nodes. Any objections?

>
> diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
> index 5b17cc8..4dc2e64 100644
> --- a/drivers/pnp/pnpacpi/core.c
> +++ b/drivers/pnp/pnpacpi/core.c
> @@ -243,6 +243,10 @@ static int __init pnpacpi_add_device(struct acpi_device *device)
> char *pnpid;
> struct acpi_hardware_id *id;
>
> + /* Skip devices that are already bound */
> + if (device->physical_node_count)
> + return 0;
> +
> /*
> * If a PnPacpi device is not present , the device
> * driver should not be loaded.
>
>