On Tuesday, February 10, 2015 11:59:32 AM Mika Westerberg wrote: > 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. I agree. > Besides, how do you support modules with this? Or did I miss something? Good question. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
