Am 27.03.24 um 22:45 schrieb Armin Wolf:
Since commit e2ffcda16290 ("ACPI: OSL: Allow Notify () handlers to run on all CPUs"), the ACPI core allows multiple notify calls to be active at the same time. This means that two instances of quickstart_notify() running at the same time can mess which each others input sequences. Fix this by protecting the input sequence with a mutex. Compile-tested only.
Any thoughts on this? Armin Wolf
Fixes: afd66f2a739e ("platform/x86: Add ACPI quickstart button (PNP0C32) driver") Signed-off-by: Armin Wolf <W_Armin@xxxxxx> --- This applies on the branch "review-hans". Maybe we could somehow document the concurrency rules for ACPI notify handlers? --- drivers/platform/x86/quickstart.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/platform/x86/quickstart.c b/drivers/platform/x86/quickstart.c index ba3a7a25dda7..e40f852d42c1 100644 --- a/drivers/platform/x86/quickstart.c +++ b/drivers/platform/x86/quickstart.c @@ -18,6 +18,7 @@ #include <linux/input/sparse-keymap.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/platform_device.h> #include <linux/sysfs.h> #include <linux/types.h> @@ -35,6 +36,7 @@ struct quickstart_data { struct device *dev; + struct mutex input_lock; /* Protects input sequence during notify */ struct input_dev *input_device; char input_name[32]; char phys[32]; @@ -73,7 +75,10 @@ static void quickstart_notify(acpi_handle handle, u32 event, void *context) switch (event) { case QUICKSTART_EVENT_RUNTIME: + mutex_lock(&data->input_lock); sparse_keymap_report_event(data->input_device, 0x1, 1, true); + mutex_unlock(&data->input_lock); + acpi_bus_generate_netlink_event(DRIVER_NAME, dev_name(data->dev), event, 0); break; default: @@ -147,6 +152,13 @@ static void quickstart_notify_remove(void *context) acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, quickstart_notify); } +static void quickstart_mutex_destroy(void *data) +{ + struct mutex *lock = data; + + mutex_destroy(lock); +} + static int quickstart_probe(struct platform_device *pdev) { struct quickstart_data *data; @@ -165,6 +177,11 @@ static int quickstart_probe(struct platform_device *pdev) data->dev = &pdev->dev; dev_set_drvdata(&pdev->dev, data); + mutex_init(&data->input_lock); + ret = devm_add_action_or_reset(&pdev->dev, quickstart_mutex_destroy, &data->input_lock); + if (ret < 0) + return ret; + /* We have to initialize the device wakeup before evaluating GHID because * doing so will notify the device if the button was used to wake the machine * from S5. -- 2.39.2