[PATCH v3 3/5] Input: applespi - register touchpad synchronously in probe
From: Shih-Yuan Lee <hidden>
Date: 2026-07-20 16:22:31
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
Replace the asynchronous worker for touchpad registration with synchronous registration during driver probe. Wait up to 3 seconds for the device info packet and fallback to keyboard-only mode if a timeout occurs. Prevent a kernel panic in debugfs by checking for a NULL touchpad_input_dev in applespi_tp_dim_open() before dereferencing it, returning -ENODEV if the device is operating in keyboard-only mode. Protect rcvd_tp_info from data races by creating a local copy under cmd_msg_lock before passing it to applespi_register_touchpad_device(). Signed-off-by: Shih-Yuan Lee <redacted> --- drivers/input/keyboard/applespi.c | 60 ++++++++++++++++++++++--------- 1 file changed, 44 insertions(+), 16 deletions(-)
diff --git a/drivers/input/keyboard/applespi.c b/drivers/input/keyboard/applespi.c
index c9bbceaf0671..6db4eeca3060 100644
--- a/drivers/input/keyboard/applespi.c
+++ b/drivers/input/keyboard/applespi.c@@ -427,7 +427,7 @@ struct applespi_data { } spi_complete[2]; bool cancel_spi; - struct work_struct work; + bool have_tp_info; struct touchpad_info_protocol rcvd_tp_info; struct dentry *debugfs_root;
@@ -1030,6 +1030,9 @@ static int applespi_tp_dim_open(struct inode *inode, struct file *file) { struct applespi_data *applespi = inode->i_private; + if (!applespi->touchpad_input_dev) + return -ENODEV; + file->private_data = applespi; snprintf(applespi->tp_dim_val, sizeof(applespi->tp_dim_val),
@@ -1390,26 +1393,20 @@ 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) { + unsigned long flags; + 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. - */ + spin_lock_irqsave(&applespi->cmd_msg_lock, flags); applespi->rcvd_tp_info = message->tp_info; - schedule_work(&applespi->work); + applespi->have_tp_info = true; + spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags); + + wake_up_all(&applespi->wait_queue); return; }
@@ -1677,6 +1674,7 @@ static int applespi_probe(struct spi_device *spi) acpi_handle spi_handle = ACPI_HANDLE(&spi->dev); acpi_status acpi_sts; int sts, i; + unsigned long flags; unsigned long long gpe, usb_status; /* check if the USB interface is present and enabled already */
@@ -1694,8 +1692,6 @@ 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);
@@ -1823,6 +1819,25 @@ static int applespi_probe(struct spi_device *spi) /* trigger touchpad setup */ applespi_init(applespi, false); + /* set up the touchpad as a separate input device if info is received */ + sts = wait_event_timeout(applespi->wait_queue, + READ_ONCE(applespi->have_tp_info), + msecs_to_jiffies(3000)); + if (!sts) { + dev_warn(&applespi->spi->dev, + "Timed out waiting for touchpad info, continuing keyboard-only\n"); + } else { + struct touchpad_info_protocol tp_info; + + spin_lock_irqsave(&applespi->cmd_msg_lock, flags); + tp_info = applespi->rcvd_tp_info; + spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags); + + sts = applespi_register_touchpad_device(applespi, &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
@@ -1855,6 +1870,19 @@ static int applespi_probe(struct spi_device *spi) &applespi_tp_dim_fops); 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)
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2.39.5