Re: [PATCH 3/4] fix module autoloading for ACPI enumerated devices

From: Zhang Rui
Date: Tue Jan 14 2014 - 20:16:57 EST


On Tue, 2014-01-14 at 14:41 +0000, Mark Brown wrote:
> On Tue, Jan 14, 2014 at 04:00:17PM +0800, Zhang Rui wrote:
> > On Mon, 2014-01-13 at 17:35 +0000, Mark Brown wrote:
> > > On Mon, Jan 13, 2014 at 09:48:31PM +0800, Zhang Rui wrote:
> > > > ACPI enumerated devices has ACPI style _HID and _CID strings,
> > > > all of these strings can be used for both driver loading and matching.
>
> > If this piece of code is used in an *SPI* driver for an ACPI enumerated
> > spi device, the spi driver module_alias is "acpi:INTABCD", but
> > the uevent of its spi device node is
> > "spi:INTABCD" (PREFIX:spi_device->modalias).
>
> OK that makes sense, but what does this have to do with the _HID and
> _CID methods?

If an ACPI enumerated SPI device has a _HID and a _CID,
both of them need to be exposed in 'uevent', so that a driver that
matches _CID can also have a chance to be probed. This can not be done
by the current code, thus we need special handling of ACPI enumerated
SPI devices.

> Surely we're just replacing spi: with acpi: in the uevent?

yes.

thanks,
rui

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