include/video/udlfb.h
Source file repositories/reference/linux-study-clean/include/video/udlfb.h
File Facts
- System
- Linux kernel
- Corpus path
include/video/udlfb.h- Extension
.h- Size
- 2998 bytes
- Lines
- 105
- Domain
- Repository Root And Misc
- Bucket
- include
- Inferred role
- Repository Root And Misc: implementation source
- Status
- source implementation candidate
Why This File Exists
Top-level or miscellaneous repository surface. Use this as map coverage unless a later manual pass promotes the file into a deeper subsystem dossier.
- Top-level or miscellaneous repository surface. Use this as map coverage unless a later manual pass promotes the file into a deeper subsystem dossier.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
struct dloareastruct urb_nodestruct urb_liststruct dlfb_data
Annotated Snippet
struct dloarea {
int x, y;
int w, h;
int x2, y2;
};
struct urb_node {
struct list_head entry;
struct dlfb_data *dlfb;
struct urb *urb;
};
struct urb_list {
struct list_head list;
spinlock_t lock;
struct semaphore limit_sem;
int available;
int count;
size_t size;
};
struct dlfb_data {
struct usb_device *udev;
struct fb_info *info;
struct urb_list urbs;
char *backing_buffer;
int fb_count;
bool virtualized; /* true when physical usb device not present */
atomic_t usb_active; /* 0 = update virtual buffer, but no usb traffic */
atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */
char *edid; /* null until we read edid from hw or get from sysfs */
size_t edid_size;
int sku_pixel_limit;
int base16;
int base8;
u32 pseudo_palette[256];
int blank_mode; /*one of FB_BLANK_ */
struct mutex render_mutex;
int damage_x;
int damage_y;
int damage_x2;
int damage_y2;
spinlock_t damage_lock;
struct work_struct damage_work;
struct fb_ops ops;
atomic_t mmap_count;
/* blit-only rendering path metrics, exposed through sysfs */
atomic_t bytes_rendered; /* raw pixel-bytes driver asked to render */
atomic_t bytes_identical; /* saved effort with backbuffer comparison */
atomic_t bytes_sent; /* to usb, after compression including overhead */
atomic_t cpu_kcycles_used; /* transpired during pixel processing */
struct fb_var_screeninfo current_mode;
struct list_head deferred_free;
};
#define NR_USB_REQUEST_I2C_SUB_IO 0x02
#define NR_USB_REQUEST_CHANNEL 0x12
/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
#define BULK_SIZE 512
#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
#define WRITES_IN_FLIGHT (4)
#define MAX_VENDOR_DESCRIPTOR_SIZE 256
#define GET_URB_TIMEOUT HZ
#define FREE_URB_TIMEOUT (HZ*2)
#define BPP 2
#define MAX_CMD_PIXELS 255
#define RLX_HEADER_BYTES 7
#define MIN_RLX_PIX_BYTES 4
#define MIN_RLX_CMD_BYTES (RLX_HEADER_BYTES + MIN_RLX_PIX_BYTES)
#define RLE_HEADER_BYTES 6
#define MIN_RLE_PIX_BYTES 3
#define MIN_RLE_CMD_BYTES (RLE_HEADER_BYTES + MIN_RLE_PIX_BYTES)
#define RAW_HEADER_BYTES 6
#define MIN_RAW_PIX_BYTES 2
#define MIN_RAW_CMD_BYTES (RAW_HEADER_BYTES + MIN_RAW_PIX_BYTES)
#define DL_DEFIO_WRITE_DELAY msecs_to_jiffies(HZ <= 300 ? 4 : 10) /* optimal value for 720p video */
#define DL_DEFIO_WRITE_DISABLE (HZ*60) /* "disable" with long delay */
/* remove these once align.h patch is taken into kernel */
#define DL_ALIGN_UP(x, a) ALIGN(x, a)
#define DL_ALIGN_DOWN(x, a) ALIGN_DOWN(x, a)
Annotation
- Detected declarations: `struct dloarea`, `struct urb_node`, `struct urb_list`, `struct dlfb_data`.
- Atlas domain: Repository Root And Misc / include.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.