From 8373a3e512c8ea8e93981d42b0d1efb252be17fa Mon Sep 17 00:00:00 2001 From: Brandon Philips Date: Tue, 24 Jun 2008 22:58:25 -0300 Subject: [PATCH] V4L/DVB (8389): videodev: simplify get_index() Use Hans Verkuil's suggested method of implementing get_index which doesn't depend on class_for_each_device and instead uses the video_device array. This simplifies the code and reduces its memory footprint. Signed-off-by: Brandon Philips Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/videodev.c | 65 +++++++++------------------------- 1 file changed, 17 insertions(+), 48 deletions(-) diff --git a/drivers/media/video/videodev.c b/drivers/media/video/videodev.c index c24d9189709..bf12b5f850e 100644 --- a/drivers/media/video/videodev.c +++ b/drivers/media/video/videodev.c @@ -2011,25 +2011,8 @@ out: } EXPORT_SYMBOL(video_ioctl2); -struct index_info { - struct device *dev; - unsigned int used[VIDEO_NUM_DEVICES]; -}; - -static int __fill_index_info(struct device *cd, void *data) -{ - struct index_info *info = data; - struct video_device *vfd = container_of(cd, struct video_device, - class_dev); - - if (info->dev == vfd->dev) - info->used[vfd->index] = 1; - - return 0; -} - /** - * assign_index - assign stream number based on parent device + * get_index - assign stream number based on parent device * @vdev: video_device to assign index number to, vdev->dev should be assigned * @num: -1 if auto assign, requested number otherwise * @@ -2039,44 +2022,30 @@ static int __fill_index_info(struct device *cd, void *data) */ static int get_index(struct video_device *vdev, int num) { - struct index_info *info; + u32 used = 0; int i; - int ret = 0; - if (num >= VIDEO_NUM_DEVICES) + if (num >= 32) { + printk(KERN_ERR "videodev: %s num is too large\n", __func__); return -EINVAL; - - info = kzalloc(sizeof(*info), GFP_KERNEL); - if (!info) - return -ENOMEM; - - info->dev = vdev->dev; - - ret = class_for_each_device(&video_class, info, - __fill_index_info); - - if (ret < 0) - goto out; - - if (num >= 0) { - if (!info->used[num]) - ret = num; - else - ret = -ENFILE; - - goto out; } for (i = 0; i < VIDEO_NUM_DEVICES; i++) { - if (info->used[i]) - continue; - ret = i; - goto out; + if (video_device[i] != NULL && + video_device[i] != vdev && + video_device[i]->dev == vdev->dev) { + used |= 1 << video_device[i]->index; + } } -out: - kfree(info); - return ret; + if (num >= 0) { + if (used & (1 << num)) + return -ENFILE; + return num; + } + + i = ffz(used); + return i >= 32 ? -ENFILE : i; } static const struct file_operations video_fops; -- 2.41.1