This allows errors during registration to properly fail the probe
function.

Doing this requires waiting for a response from the device inside the
probe function. While this generally takes about 15ms, in case of errors
it could be arbitrarily long, and hence a 3 second timeout is used.

This also adds 3 second timeouts to the drain functions to avoid the
potential for suspend or remove hanging forever.

Signed-off-by: Ronald Tschalär <ron...@innovation.ch>
---
Changes in v2:
  merged the two wait-queue's into one

 drivers/input/keyboard/applespi.c | 132 +++++++++++++++++++++++-------
 1 file changed, 103 insertions(+), 29 deletions(-)

diff --git a/drivers/input/keyboard/applespi.c 
b/drivers/input/keyboard/applespi.c
index 548737e7aeda..d5defdefbc34 100644
--- a/drivers/input/keyboard/applespi.c
+++ b/drivers/input/keyboard/applespi.c
@@ -48,12 +48,12 @@
 #include <linux/efi.h>
 #include <linux/input.h>
 #include <linux/input/mt.h>
+#include <linux/jiffies.h>
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/spi/spi.h>
 #include <linux/wait.h>
-#include <linux/workqueue.h>
 
 #include <asm/barrier.h>
 #include <asm/unaligned.h>
@@ -405,13 +405,19 @@ struct applespi_data {
 
        struct led_classdev             backlight_info;
 
+       wait_queue_head_t               wait_queue;
+
        bool                            suspended;
        bool                            drain;
-       wait_queue_head_t               drain_complete;
        bool                            read_active;
        bool                            write_active;
 
-       struct work_struct              work;
+       struct applespi_complete_info {
+               void                            (*complete)(void *context);
+               struct applespi_data            *applespi;
+       }                               spi_complete[2];
+       bool                            cancel_spi;
+
        struct touchpad_info_protocol   rcvd_tp_info;
 
        struct dentry                   *debugfs_root;
@@ -593,13 +599,61 @@ static void applespi_setup_write_txfrs(struct 
applespi_data *applespi)
        spi_message_add_tail(st_t, msg);
 }
 
+static bool applespi_async_outstanding(struct applespi_data *applespi)
+{
+       return applespi->spi_complete[0].complete ||
+              applespi->spi_complete[1].complete;
+}
+
+static void applespi_async_complete(void *context)
+{
+       struct applespi_complete_info *info = context;
+       struct applespi_data *applespi = info->applespi;
+       unsigned long flags;
+
+       info->complete(applespi);
+
+       spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+
+       info->complete = NULL;
+
+       if (applespi->cancel_spi && !applespi_async_outstanding(applespi))
+               wake_up_all(&applespi->wait_queue);
+
+       spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+}
+
 static int applespi_async(struct applespi_data *applespi,
                          struct spi_message *message, void (*complete)(void *))
 {
-       message->complete = complete;
-       message->context = applespi;
+       struct applespi_complete_info *info;
+       int sts;
+
+       if (applespi->cancel_spi) {
+               if (!applespi_async_outstanding(applespi))
+                       wake_up_all(&applespi->wait_queue);
+               return -ESHUTDOWN;
+       }
+
+       /*
+        * There can only be at most 2 spi requests in flight, one for "reads"
+        * and one for "writes".
+        */
+       if (!applespi->spi_complete[0].complete)
+               info = &applespi->spi_complete[0];
+       else
+               info = &applespi->spi_complete[1];
+       info->complete = complete;
+       info->applespi = applespi;
+
+       message->complete = applespi_async_complete;
+       message->context = info;
+
+       sts = spi_async(applespi->spi, message);
+       if (sts)
+               info->complete = NULL;
 
-       return spi_async(applespi->spi, message);
+       return sts;
 }
 
 static inline bool applespi_check_write_status(struct applespi_data *applespi,
@@ -663,7 +717,7 @@ static int applespi_setup_spi(struct applespi_data 
*applespi)
                return sts;
 
        spin_lock_init(&applespi->cmd_msg_lock);
-       init_waitqueue_head(&applespi->drain_complete);
+       init_waitqueue_head(&applespi->wait_queue);
 
        return 0;
 }
@@ -713,7 +767,7 @@ static void applespi_msg_complete(struct applespi_data 
*applespi,
                applespi->write_active = false;
 
        if (applespi->drain && !applespi->write_active)
-               wake_up_all(&applespi->drain_complete);
+               wake_up_all(&applespi->wait_queue);
 
        if (is_write_msg) {
                applespi->cmd_msg_queued = false;
@@ -1011,7 +1065,7 @@ static void report_tp_state(struct applespi_data 
*applespi,
        const struct applespi_tp_info *tp_info = &applespi->tp_info;
        int i, n;
 
-       /* touchpad_input_dev is set async in worker */
+       /* touchpad_input_dev is set async in probe */
        input = smp_load_acquire(&applespi->touchpad_input_dev);
        if (!input)
                return; /* touchpad isn't initialized yet */
@@ -1315,26 +1369,14 @@ applespi_register_touchpad_device(struct applespi_data 
*applespi,
        return 0;
 }
 
-static void applespi_worker(struct work_struct *work)
-{
-       struct applespi_data *applespi =
-               container_of(work, struct applespi_data, work);
-
-       applespi_register_touchpad_device(applespi, &applespi->rcvd_tp_info);
-}
-
 static void applespi_handle_cmd_response(struct applespi_data *applespi,
                                         struct spi_packet *packet,
                                         struct message *message)
 {
        if (packet->device == PACKET_DEV_INFO &&
            le16_to_cpu(message->type) == 0x1020) {
-               /*
-                * We're not allowed to sleep here, but registering an input
-                * device can sleep.
-                */
                applespi->rcvd_tp_info = message->tp_info;
-               schedule_work(&applespi->work);
+               wake_up_all(&applespi->wait_queue);
                return;
        }
 
@@ -1408,7 +1450,7 @@ static void applespi_got_data(struct applespi_data 
*applespi)
                        applespi->read_active = false;
                        applespi->write_active = false;
 
-                       wake_up_all(&applespi->drain_complete);
+                       wake_up_all(&applespi->wait_queue);
                }
 
                spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
@@ -1623,6 +1665,7 @@ static int applespi_probe(struct spi_device *spi)
        struct applespi_data *applespi;
        acpi_handle spi_handle = ACPI_HANDLE(&spi->dev);
        acpi_status acpi_sts;
+       unsigned long flags;
        int sts, i;
        unsigned long long gpe, usb_status;
 
@@ -1641,8 +1684,6 @@ static int applespi_probe(struct spi_device *spi)
 
        applespi->spi = spi;
 
-       INIT_WORK(&applespi->work, applespi_worker);
-
        /* store the driver data */
        spi_set_drvdata(spi, applespi);
 
@@ -1770,6 +1811,22 @@ static int applespi_probe(struct spi_device *spi)
        /* trigger touchpad setup */
        applespi_init(applespi, false);
 
+       /* set up the touchpad as a separate input device */
+       sts = wait_event_timeout(applespi->wait_queue,
+                                applespi->rcvd_tp_info.model_no,
+                                msecs_to_jiffies(3000));
+       if (!sts) {
+               dev_err(&applespi->spi->dev,
+                       "Timed out waiting for device info\n");
+               sts = -ETIMEDOUT;
+               goto cancel_spi;
+       }
+
+       sts = applespi_register_touchpad_device(applespi,
+                                               &applespi->rcvd_tp_info);
+       if (sts)
+               goto cancel_spi;
+
        /*
         * By default this device is not enabled for wakeup; but USB keyboards
         * generally are, so the expectation is that by default the keyboard
@@ -1820,6 +1877,19 @@ static int applespi_probe(struct spi_device *spi)
        }
 
        return 0;
+
+cancel_spi:
+       acpi_disable_gpe(NULL, applespi->gpe);
+       acpi_remove_gpe_handler(NULL, applespi->gpe, applespi_notify);
+
+       spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+       applespi->cancel_spi = true;
+       wait_event_lock_irq(applespi->wait_queue,
+                           !applespi_async_outstanding(applespi),
+                           applespi->cmd_msg_lock);
+       spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+
+       return sts;
 }
 
 static void applespi_drain_writes(struct applespi_data *applespi)
@@ -1829,8 +1899,10 @@ static void applespi_drain_writes(struct applespi_data 
*applespi)
        spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
 
        applespi->drain = true;
-       wait_event_lock_irq(applespi->drain_complete, !applespi->write_active,
-                           applespi->cmd_msg_lock);
+       wait_event_lock_irq_timeout(applespi->wait_queue,
+                                   !applespi->write_active,
+                                   applespi->cmd_msg_lock,
+                                   msecs_to_jiffies(3000));
 
        spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
 }
@@ -1841,8 +1913,10 @@ static void applespi_drain_reads(struct applespi_data 
*applespi)
 
        spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
 
-       wait_event_lock_irq(applespi->drain_complete, !applespi->read_active,
-                           applespi->cmd_msg_lock);
+       wait_event_lock_irq_timeout(applespi->wait_queue,
+                                   !applespi->read_active,
+                                   applespi->cmd_msg_lock,
+                                   msecs_to_jiffies(3000));
 
        applespi->suspended = true;
 
-- 
2.21.0

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