From 1a373d15e283937b51eaf5debf4fc31474c31436 Mon Sep 17 00:00:00 2001 From: Yurii Pavlovskyi Date: Tue, 14 May 2019 21:02:09 +0200 Subject: [PATCH] platform/x86: asus-wmi: Support WMI event queue Event codes are expected to be retrieved from a queue on at least some models. Specifically, very likely the ACPI WMI devices with _UID ATK are queued whereas those with ASUSWMI are not [1]. The WMI event codes are pushed into a circular buffer queue. After the INIT method is called, ACPI code is allowed to push events into this buffer. The INIT method cannot be reverted. If the module is unloaded and an event (such as hotkey press) gets emitted before inserting it back the events get processed delayed by one or if the queue overflows, additionally delayed by about 3 seconds. It might be considered a minor issue and no normal user would likely observe this (there is little reason unloading the driver), but it does significantly frustrate a developer who is unlucky enough to encounter this. Therefore, the fallback to unqueued behavior occurs whenever something unexpected happens. The fix flushes the old key codes out of the queue on load. After receiving event the queue is read until either ..FFFF or 1 is encountered. Also as noted in [1] it is checked whether notify code is equal to 0xFF before enabling queue processing in WMI notify handler. DSDT examples: FX505GM Device (ATKD) { .. Name (ATKQ, Package (0x10) { 0xFFFFFFFF, .. } Method (IANQ, 1, Serialized) { If ((AQNO >= 0x10)) { Local0 = 0x64 While ((Local0 && (AQNO >= 0x10))) { Local0-- Sleep (0x0A) } ... .. AQTI++ AQTI &= 0x0F ATKQ [AQTI] = Arg0 ... } Method (GANQ, 0, Serialized) { .. If (AQNO) { ... Local0 = DerefOf (ATKQ [AQHI]) AQHI++ AQHI &= 0x0F Return (Local0) } Return (One) } This code is almost identical to K54C, which does return Ones on empty queue. K54C: Method (GANQ, 0, Serialized) { If (AQNO) { ... Return (Local0) } Return (Ones) } [1] Link: https://lkml.org/lkml/2019/4/12/104 Signed-off-by: Yurii Pavlovskyi Suggested-by: Daniel Drake Signed-off-by: Andy Shevchenko --- drivers/platform/x86/asus-wmi.c | 73 ++++++++++++++++++++++++++++++--- 1 file changed, 68 insertions(+), 5 deletions(-) diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c index fc4ccdedb626..83bf145e9ca5 100644 --- a/drivers/platform/x86/asus-wmi.c +++ b/drivers/platform/x86/asus-wmi.c @@ -84,6 +84,13 @@ MODULE_LICENSE("GPL"); #define PCI_DEVICE_ID_INTEL_LYNXPOINT_LP_XHCI 0x9c31 #define ASUS_ACPI_UID_ASUSWMI "ASUSWMI" +#define ASUS_ACPI_UID_ATK "ATK" + +#define WMI_EVENT_QUEUE_SIZE 0x10 +#define WMI_EVENT_QUEUE_END 0x1 +#define WMI_EVENT_MASK 0xFFFF +/* The WMI hotkey event value is always the same. */ +#define WMI_EVENT_VALUE_ATK 0xFF #define WMI_EVENT_MASK 0xFFFF @@ -150,6 +157,7 @@ struct asus_wmi { int dsts_id; int spec; int sfun; + bool wmi_event_queue; struct input_dev *inputdev; struct backlight_device *backlight_device; @@ -1738,14 +1746,52 @@ static void asus_wmi_handle_event_code(int code, struct asus_wmi *asus) static void asus_wmi_notify(u32 value, void *context) { struct asus_wmi *asus = context; - int code = asus_wmi_get_event_code(value); + int code; + int i; - if (code < 0) { - pr_warn("Failed to get notify code: %d\n", code); - return; + for (i = 0; i < WMI_EVENT_QUEUE_SIZE + 1; i++) { + code = asus_wmi_get_event_code(value); + + if (code < 0) { + pr_warn("Failed to get notify code: %d\n", code); + return; + } + + if (code == WMI_EVENT_QUEUE_END || code == WMI_EVENT_MASK) + return; + + asus_wmi_handle_event_code(code, asus); + + /* + * Double check that queue is present: + * ATK (with queue) uses 0xff, ASUSWMI (without) 0xd2. + */ + if (!asus->wmi_event_queue || value != WMI_EVENT_VALUE_ATK) + return; } - asus_wmi_handle_event_code(code, asus); + pr_warn("Failed to process event queue, last code: 0x%x\n", code); +} + +static int asus_wmi_notify_queue_flush(struct asus_wmi *asus) +{ + int code; + int i; + + for (i = 0; i < WMI_EVENT_QUEUE_SIZE + 1; i++) { + code = asus_wmi_get_event_code(WMI_EVENT_VALUE_ATK); + + if (code < 0) { + pr_warn("Failed to get event during flush: %d\n", code); + return code; + } + + if (code == WMI_EVENT_QUEUE_END || code == WMI_EVENT_MASK) + return 0; + } + + pr_warn("Failed to flush event queue\n"); + return -EIO; } /* @@ -1944,6 +1990,23 @@ static int asus_wmi_platform_init(struct asus_wmi *asus) asus->dsts_id = ASUS_WMI_METHODID_DSTS; } + /* + * Some devices can have multiple event codes stored in a queue before + * the module load if it was unloaded intermittently after calling + * the INIT method (enables event handling). The WMI notify handler is + * expected to retrieve all event codes until a retrieved code equals + * queue end marker (One or Ones). Old codes are flushed from the queue + * upon module load. Not enabling this when it should be has minimal + * visible impact so fall back if anything goes wrong. + */ + wmi_uid = wmi_get_acpi_device_uid(asus->driver->event_guid); + if (wmi_uid && !strcmp(wmi_uid, ASUS_ACPI_UID_ATK)) { + dev_info(dev, "Detected ATK, enable event queue\n"); + + if (!asus_wmi_notify_queue_flush(asus)) + asus->wmi_event_queue = true; + } + /* CWAP allow to define the behavior of the Fn+F2 key, * this method doesn't seems to be present on Eee PCs */ if (asus->driver->quirks->wapf >= 0) -- 2.30.2