forked from Minki/linux
e5fbab51b4
Add a mechanism to let the write queue drain naturally before closing the TTY, rather than always losing that data. There is a timeout, so it can't wait too long. Provide missing locking inside acm_wb_is_avail(); it matters more now. Note, this presumes an earlier patch was applied, removing a call to this routine where the lock was held. Slightly improved diagnostics on write URB completion, so we can tell when a write URB gets killed and, if so, how much data it wrote first ... and so that I/O path is normally silent (and can't much change timings). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
137 lines
3.6 KiB
C
137 lines
3.6 KiB
C
/*
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*
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* Includes for cdc-acm.c
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*
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* Mainly take from usbnet's cdc-ether part
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*
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*/
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/*
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* CMSPAR, some architectures can't have space and mark parity.
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*/
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#ifndef CMSPAR
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#define CMSPAR 0
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#endif
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/*
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* Major and minor numbers.
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*/
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#define ACM_TTY_MAJOR 166
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#define ACM_TTY_MINORS 32
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/*
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* Requests.
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*/
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#define USB_RT_ACM (USB_TYPE_CLASS | USB_RECIP_INTERFACE)
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/*
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* Output control lines.
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*/
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#define ACM_CTRL_DTR 0x01
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#define ACM_CTRL_RTS 0x02
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/*
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* Input control lines and line errors.
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*/
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#define ACM_CTRL_DCD 0x01
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#define ACM_CTRL_DSR 0x02
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#define ACM_CTRL_BRK 0x04
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#define ACM_CTRL_RI 0x08
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#define ACM_CTRL_FRAMING 0x10
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#define ACM_CTRL_PARITY 0x20
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#define ACM_CTRL_OVERRUN 0x40
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/*
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* Internal driver structures.
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*/
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/*
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* The only reason to have several buffers is to accomodate assumptions
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* in line disciplines. They ask for empty space amount, receive our URB size,
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* and proceed to issue several 1-character writes, assuming they will fit.
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* The very first write takes a complete URB. Fortunately, this only happens
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* when processing onlcr, so we only need 2 buffers. These values must be
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* powers of 2.
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*/
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#define ACM_NW 16
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#define ACM_NR 16
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struct acm_wb {
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unsigned char *buf;
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dma_addr_t dmah;
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int len;
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int use;
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struct urb *urb;
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struct acm *instance;
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};
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struct acm_rb {
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struct list_head list;
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int size;
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unsigned char *base;
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dma_addr_t dma;
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};
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struct acm_ru {
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struct list_head list;
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struct acm_rb *buffer;
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struct urb *urb;
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struct acm *instance;
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};
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struct acm {
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struct usb_device *dev; /* the corresponding usb device */
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struct usb_interface *control; /* control interface */
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struct usb_interface *data; /* data interface */
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struct tty_struct *tty; /* the corresponding tty */
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struct urb *ctrlurb; /* urbs */
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u8 *ctrl_buffer; /* buffers of urbs */
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dma_addr_t ctrl_dma; /* dma handles of buffers */
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u8 *country_codes; /* country codes from device */
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unsigned int country_code_size; /* size of this buffer */
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unsigned int country_rel_date; /* release date of version */
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struct acm_wb wb[ACM_NW];
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struct acm_ru ru[ACM_NR];
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struct acm_rb rb[ACM_NR];
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int rx_buflimit;
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int rx_endpoint;
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spinlock_t read_lock;
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struct list_head spare_read_urbs;
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struct list_head spare_read_bufs;
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struct list_head filled_read_bufs;
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int write_used; /* number of non-empty write buffers */
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int processing;
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int transmitting;
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spinlock_t write_lock;
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struct mutex mutex;
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struct usb_cdc_line_coding line; /* bits, stop, parity */
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struct work_struct work; /* work queue entry for line discipline waking up */
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struct work_struct waker;
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wait_queue_head_t drain_wait; /* close processing */
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struct tasklet_struct urb_task; /* rx processing */
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spinlock_t throttle_lock; /* synchronize throtteling and read callback */
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unsigned int ctrlin; /* input control lines (DCD, DSR, RI, break, overruns) */
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unsigned int ctrlout; /* output control lines (DTR, RTS) */
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unsigned int writesize; /* max packet size for the output bulk endpoint */
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unsigned int readsize,ctrlsize; /* buffer sizes for freeing */
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unsigned int used; /* someone has this acm's device open */
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unsigned int minor; /* acm minor number */
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unsigned char throttle; /* throttled by tty layer */
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unsigned char clocal; /* termios CLOCAL */
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unsigned int ctrl_caps; /* control capabilities from the class specific header */
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unsigned int susp_count; /* number of suspended interfaces */
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struct acm_wb *delayed_wb; /* write queued for a device about to be woken */
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};
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#define CDC_DATA_INTERFACE_TYPE 0x0a
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/* constants describing various quirks and errors */
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#define NO_UNION_NORMAL 1
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#define SINGLE_RX_URB 2
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