On Mon, Feb 09, 2015 at 09:02:11PM +0000, Suthikulpanit, Suravee wrote: > On 2/9/15, 19:15, "Mika Westerberg" <mika.westerberg@xxxxxxxxxxxxxxx> > wrote: > > >On Mon, Feb 09, 2015 at 12:02:43AM +0100, Rafael J. Wysocki wrote: > >> On Monday, February 09, 2015 12:20:03 AM Suravee Suthikulpanit wrote: > >> > Device drivers typically use ACPI _HIDs/_CIDs listed in struct > >>device_driver > >> > acpi_match_table to match devices. However, for generic drivers, we do > >> > not want to list _HID for all supported devices, and some device > >>classes > >> > do not have _CID (e.g. SATA, USB). Instead, we can leverage ACPI _CLS, > >> > which specifies PCI-defined class code (i.e. base-class, subclass and > >> > programming interface). > >> > > >> > This patch adds support for matching ACPI devices using the _CLS > >>method. > >> > > >> > Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> > >> > >> Greg, Mika, any problems with this? > > > >Is there some specific reason why this cannot be done in similar way > >than PCI already does? > > > >In other words, stuff _CLS fields to struct acpi_device_id and make > >match functions match against those if they are != 0. > > That was my original thought. Then I realized that the acpi_device_id is > used > to create the device matching table, in which could contain several > _HID/_CID. > However, most of the added _CLS field would likely ended up being unused > and > taking up space. Well, PCI is doing that already :) > In contrast to _HID/_CID, a driver is likely to match just a single _CLS. > So, I think it is cleaner to have just a dedicate struct acpi_device_cls, > and > a matching function for it. IMHO cleaner version is the one following PCI. Besides, how do you support modules with this? Or did I miss something? -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
