| From 35d4670aaec7206b5ef19c842ca33076bde562e4 Mon Sep 17 00:00:00 2001 |
| From: =?UTF-8?q?Ronald=20Tschal=C3=A4r?= <ronald@innovation.ch> |
| Date: Tue, 11 Feb 2020 11:47:23 -0800 |
| Subject: serdev: Fix detection of UART devices on Apple machines. |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Ronald Tschalär <ronald@innovation.ch> |
| |
| commit 35d4670aaec7206b5ef19c842ca33076bde562e4 upstream. |
| |
| 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> |
| |
| --- |
| drivers/tty/serdev/core.c | 10 ++++++++++ |
| 1 file changed, 10 insertions(+) |
| |
| --- 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); |
| @@ -630,6 +631,15 @@ static int acpi_serdev_check_resources(s |
| 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; |
