diff options
Diffstat (limited to 'drivers/gpio/gpiolib-cdev.c')
| -rw-r--r-- | drivers/gpio/gpiolib-cdev.c | 89 |
1 files changed, 47 insertions, 42 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 5639abce6ec5..78c9d9ed3d68 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -1132,6 +1132,14 @@ static void edge_detector_stop(struct line *line) /* do not change line->level - see comment in debounced_value() */ } +static int edge_detector_fifo_init(struct linereq *req) +{ + if (kfifo_initialized(&req->events)) + return 0; + + return kfifo_alloc(&req->events, req->event_buffer_size, GFP_KERNEL); +} + static int edge_detector_setup(struct line *line, struct gpio_v2_line_config *lc, unsigned int line_idx, u64 edflags) @@ -1143,9 +1151,8 @@ static int edge_detector_setup(struct line *line, char *label; eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; - if (eflags && !kfifo_initialized(&line->req->events)) { - ret = kfifo_alloc(&line->req->events, - line->req->event_buffer_size, GFP_KERNEL); + if (eflags) { + ret = edge_detector_fifo_init(line->req); if (ret) return ret; } @@ -1197,8 +1204,6 @@ static int edge_detector_update(struct line *line, struct gpio_v2_line_config *lc, unsigned int line_idx, u64 edflags) { - u64 eflags; - int ret; u64 active_edflags = READ_ONCE(line->edflags); unsigned int debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); @@ -1214,14 +1219,9 @@ static int edge_detector_update(struct line *line, * ensure event fifo is initialised if edge detection * is now enabled. */ - eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; - if (eflags && !kfifo_initialized(&line->req->events)) { - ret = kfifo_alloc(&line->req->events, - line->req->event_buffer_size, - GFP_KERNEL); - if (ret) - return ret; - } + if (edflags & GPIO_V2_LINE_EDGE_FLAGS) + return edge_detector_fifo_init(line->req); + return 0; } @@ -1648,16 +1648,15 @@ static ssize_t linereq_read(struct file *file, char __user *buf, return ret; } - ret = kfifo_out(&lr->events, &le, 1); - } - if (ret != 1) { - /* - * This should never happen - we were holding the - * lock from the moment we learned the fifo is no - * longer empty until now. - */ - ret = -EIO; - break; + if (kfifo_out(&lr->events, &le, 1) != 1) { + /* + * This should never happen - we hold the + * lock from the moment we learned the fifo + * is no longer empty until now. + */ + WARN(1, "failed to read from non-empty kfifo"); + return -EIO; + } } if (copy_to_user(buf + bytes_read, &le, sizeof(le))) @@ -1780,6 +1779,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) mutex_init(&lr->config_mutex); init_waitqueue_head(&lr->wait); + INIT_KFIFO(lr->events); lr->event_buffer_size = ulr.event_buffer_size; if (lr->event_buffer_size == 0) lr->event_buffer_size = ulr.num_lines * 16; @@ -2000,16 +2000,15 @@ static ssize_t lineevent_read(struct file *file, char __user *buf, return ret; } - ret = kfifo_out(&le->events, &ge, 1); - } - if (ret != 1) { - /* - * This should never happen - we were holding the lock - * from the moment we learned the fifo is no longer - * empty until now. - */ - ret = -EIO; - break; + if (kfifo_out(&le->events, &ge, 1) != 1) { + /* + * This should never happen - we hold the + * lock from the moment we learned the fifo + * is no longer empty until now. + */ + WARN(1, "failed to read from non-empty kfifo"); + return -EIO; + } } if (copy_to_user(buf + bytes_read, &ge, ge_size)) @@ -2712,12 +2711,15 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, if (count < event_size) return -EINVAL; #endif - ret = kfifo_out(&cdev->events, &event, 1); - } - if (ret != 1) { - ret = -EIO; - break; - /* We should never get here. See lineevent_read(). */ + if (kfifo_out(&cdev->events, &event, 1) != 1) { + /* + * This should never happen - we hold the + * lock from the moment we learned the fifo + * is no longer empty until now. + */ + WARN(1, "failed to read from non-empty kfifo"); + return -EIO; + } } #ifdef CONFIG_GPIO_CDEV_V1 @@ -2746,7 +2748,9 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, * gpio_chrdev_open() - open the chardev for ioctl operations * @inode: inode for this chardev * @file: file struct for storing private data - * Returns 0 on success + * + * Returns: + * 0 on success, or negative errno on failure. */ static int gpio_chrdev_open(struct inode *inode, struct file *file) { @@ -2812,7 +2816,9 @@ out_free_cdev: * gpio_chrdev_release() - close chardev after ioctl operations * @inode: inode for this chardev * @file: file struct for storing private data - * Returns 0 on success + * + * Returns: + * 0 on success, or negative errno on failure. */ static int gpio_chrdev_release(struct inode *inode, struct file *file) { @@ -2836,7 +2842,6 @@ static const struct file_operations gpio_fileops = { .poll = lineinfo_watch_poll, .read = lineinfo_watch_read, .owner = THIS_MODULE, - .llseek = no_llseek, .unlocked_ioctl = gpio_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = gpio_ioctl_compat, |