Re: [PATCH] ACPI: add support for CSRT table

From: Rafael J. Wysocki
Date: Wed Jan 16 2013 - 09:59:05 EST


On Wednesday, January 16, 2013 06:42:16 AM Mika Westerberg wrote:
> On Wed, Jan 16, 2013 at 12:35:56AM +0100, Rafael J. Wysocki wrote:
> > On Monday, January 14, 2013 11:51:51 AM Mika Westerberg wrote:
> > > Core System Resources Table (CSRT) is a proprietary ACPI table that
> > > contains resources for certain devices that are not found in the DSDT
> > > table. Typically a shared DMA controller might be found here.
> > >
> > > This patch adds support for this table. We go through all entries in the
> > > table and make platform devices of them. The resources from the table are
> > > passed with the platform device.
> > >
> > > There is one special resource in the table and it is the DMA request line
> > > base and number of request lines. This information might be needed by the
> > > DMA controller driver as it needs to map the ACPI DMA request line number
> > > to the actual request line understood by the hardware. This range is passed
> > > as IORESOURCE_DMA resource.
> >
> > I have a question: Who's going to bind to those platform devices created
> > by the code in this patch and how exactly this is going to happen?
>
> Typically it is the DMA driver (but not limited to that). It is supposed to
> work so that either the driver name (in the platform driver struct) matches
> the device name in the CSRT or like with the dw_dmac case we do something
> like:
>
> /* The platform device created is "INTL9C60.0.auto" */
>
> static const struct platform_device_id dw_dma_ids[] = {
> { "INTL9C60", 0 },
> { }
> }
>
> static struct platform_driver dw_driver = {
> ...
> .id_table = dw_dma_ids,
> };

OK, that's fine by me. Will apply.

Do you want it to go to any particular branch (eg. along with the acpi-scan
changes)?

Rafael


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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