On Thursday, November 19, 2015 12:11:49 PM Mika Westerberg wrote: > On Thu, Nov 19, 2015 at 11:05:25AM +0800, Aaron Lu wrote: > > Some ACPI node's _STA will touch operation region field, since the > > evaluation of _STA in acpi_bus_type_and_status is very early, the > > operation region handler is not ready yet. Instead of fail that function > > and not creating the acpi_device node consequently, set status to 0 so > > that later when the driver for that device is probing, it can find > > the acpi_device node and proceed normally. And at that time, the > > handler for the operation region is ready and its _STA evaluation will > > succeed, its present status can be checked there. > > > > Even there will be no driver using this node later, it doesn't seem > > hurt to have one more acpi_device node created with status set to 0. > > > > This happens on Microsoft Surface 3, where the SPI device node NTRG's > > _STA touches GPIO fields and the SPI core driver will only enumerate SPI > > devices from ACPI if the acpi_device node is 1: created; 2: _STA > > indicates it's present. > > > > Note that due to another problem in SPI driver, for NTRG to be actually > > enumerated, some changes have to be made in the SPI layer, which is > > addressed by Mika(not send out yet): > > https://bugzilla.kernel.org/show_bug.cgi?id=104291#c23 > > > > Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=104291 > > Reported-by: Bastien Nocera <bugzilla@xxxxxxxxxx> > > Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> > > I don't know any better solution to this, > > Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> Applied, thanks! Rafael -- 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
