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toshiba_bluetooth: Fix enabling/disabling loop on recent devices

Bug 93911 reported a broken handling of the BT device, causing the
driver to get stuck in a loop enabling/disabling the device whenever
the device is deactivated by the kill switch as follows:

1. The user activated the kill switch, causing the system to generate
   a 0x90 (status change) event and disabling the BT device.
2. The driver catches the event and re-enables the BT device.
3. The system detects the device being activated, but since the kill
   switch is activated, disables the BT device (again) and generates
   a 0x90 event (again).
4. Repeat from 2.

This patch adds an extra check to verify the status of the BT device,
returning silently if it is already activated.

Also, checks and returns appropriate error values while evaluating
the AUSB and BTPO methods.

Signed-off-by: Azael Avalos <coproscefalo@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
hifive-unleashed-5.1
Azael Avalos 2015-03-26 14:56:07 -06:00 committed by Darren Hart
parent 18b8696b66
commit 5d3fc1d54e
1 changed files with 37 additions and 13 deletions

View File

@ -2,6 +2,7 @@
* Toshiba Bluetooth Enable Driver
*
* Copyright (C) 2009 Jes Sorensen <Jes.Sorensen@gmail.com>
* Copyright (C) 2015 Azael Avalos <coproscefalo@gmail.com>
*
* Thanks to Matthew Garrett for background info on ACPI innards which
* normal people aren't meant to understand :-)
@ -25,6 +26,10 @@
#include <linux/types.h>
#include <linux/acpi.h>
#define BT_KILLSWITCH_MASK 0x01
#define BT_PLUGGED_MASK 0x40
#define BT_POWER_MASK 0x80
MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
MODULE_LICENSE("GPL");
@ -97,29 +102,48 @@ static int toshiba_bluetooth_status(acpi_handle handle)
static int toshiba_bluetooth_enable(acpi_handle handle)
{
acpi_status res1, res2;
u64 result;
acpi_status result;
bool killswitch;
bool powered;
bool plugged;
int status;
/*
* Query ACPI to verify RFKill switch is set to 'on'.
* If not, we return silently, no need to report it as
* an error.
*/
res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
if (ACPI_FAILURE(res1))
return res1;
if (!(result & 0x01))
status = toshiba_bluetooth_status(handle);
if (status < 0)
return status;
killswitch = (status & BT_KILLSWITCH_MASK) ? true : false;
powered = (status & BT_POWER_MASK) ? true : false;
plugged = (status & BT_PLUGGED_MASK) ? true : false;
if (!killswitch)
return 0;
/*
* This check ensures to only enable the device if it is powered
* off or detached, as some recent devices somehow pass the killswitch
* test, causing a loop enabling/disabling the device, see bug 93911.
*/
if (powered || plugged)
return 0;
pr_info("Re-enabling Toshiba Bluetooth\n");
res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
return 0;
result = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
if (ACPI_FAILURE(result)) {
pr_err("Could not attach USB Bluetooth device\n");
return -ENXIO;
}
pr_warn("Failed to re-enable Toshiba Bluetooth\n");
result = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
if (ACPI_FAILURE(result)) {
pr_err("Could not power ON Bluetooth device\n");
return -ENXIO;
}
return -ENODEV;
return 0;
}
static int toshiba_bluetooth_disable(acpi_handle handle)