diff options
| author | Ronald Tschalär <ronald@innovation.ch> | 2020-02-11 22:47:23 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-06 16:10:44 +0300 |
| commit | 35d4670aaec7206b5ef19c842ca33076bde562e4 (patch) | |
| tree | ed9eb37041cfec3d57f82294e6a7769539c3ecf5 /drivers/tty/serdev | |
| parent | b85c821083359ef9fd524321af6f2a5d91730459 (diff) | |
| download | linux-35d4670aaec7206b5ef19c842ca33076bde562e4.tar.xz | |
serdev: Fix detection of UART devices on Apple machines.
On Apple devices the _CRS method returns an empty resource template, and
the resource settings are instead provided by the _DSM method. But
commit 33364d63c75d6182fa369cea80315cf1bb0ee38e (serdev: Add ACPI
devices by ResourceSource field) changed the search for serdev devices
to require valid, non-empty resource template, thereby breaking Apple
devices and causing bluetooth devices to not be found.
This expands the check so that if we don't find a valid template, and
we're on an Apple machine, then just check for the device being an
immediate child of the controller and having a "baud" property.
Cc: <stable@vger.kernel.org> # 5.5
Fixes: 33364d63c75d ("serdev: Add ACPI devices by ResourceSource field")
Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
Link: https://lore.kernel.org/r/20200211194723.486217-1-ronald@innovation.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serdev')
| -rw-r--r-- | drivers/tty/serdev/core.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index 42345e79920c..c5f0d936b003 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -18,6 +18,7 @@ #include <linux/sched.h> #include <linux/serdev.h> #include <linux/slab.h> +#include <linux/platform_data/x86/apple.h> static bool is_registered; static DEFINE_IDA(ctrl_ida); @@ -631,6 +632,15 @@ static int acpi_serdev_check_resources(struct serdev_controller *ctrl, if (ret) return ret; + /* + * Apple machines provide an empty resource template, so on those + * machines just look for immediate children with a "baud" property + * (from the _DSM method) instead. + */ + if (!lookup.controller_handle && x86_apple_machine && + !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL)) + acpi_get_parent(adev->handle, &lookup.controller_handle); + /* Make sure controller and ResourceSource handle match */ if (ACPI_HANDLE(ctrl->dev.parent) != lookup.controller_handle) return -ENODEV; |