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authorRonald Tschalär <ronald@innovation.ch>2020-02-11 22:47:23 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-03-06 16:10:44 +0300
commit35d4670aaec7206b5ef19c842ca33076bde562e4 (patch)
treeed9eb37041cfec3d57f82294e6a7769539c3ecf5 /drivers/tty/serdev
parentb85c821083359ef9fd524321af6f2a5d91730459 (diff)
downloadlinux-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.c10
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;