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. 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. Thanks, Suravee -- 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
