diff options
Diffstat (limited to 'drivers/usb/class/cdc-acm.h')
| -rw-r--r-- | drivers/usb/class/cdc-acm.h | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h index 9009114e311..963a5dfd209 100644 --- a/drivers/usb/class/cdc-acm.h +++ b/drivers/usb/class/cdc-acm.h @@ -51,14 +51,34 @@ * Internal driver structures. */ +/* + * The only reason to have several buffers is to accomodate assumptions + * in line disciplines. They ask for empty space amount, receive our URB size, + * and proceed to issue several 1-character writes, assuming they will fit. + * The very first write takes a complete URB. Fortunately, this only happens + * when processing onlcr, so we only need 2 buffers. + */ +#define ACM_NWB 2 +struct acm_wb { + unsigned char *buf; + dma_addr_t dmah; + int len; + int use; +}; + struct acm { struct usb_device *dev; /* the corresponding usb device */ struct usb_interface *control; /* control interface */ struct usb_interface *data; /* data interface */ struct tty_struct *tty; /* the corresponding tty */ struct urb *ctrlurb, *readurb, *writeurb; /* urbs */ - u8 *ctrl_buffer, *read_buffer, *write_buffer; /* buffers of urbs */ - dma_addr_t ctrl_dma, read_dma, write_dma; /* dma handles of buffers */ + u8 *ctrl_buffer, *read_buffer; /* buffers of urbs */ + dma_addr_t ctrl_dma, read_dma; /* dma handles of buffers */ + struct acm_wb wb[ACM_NWB]; + int write_current; /* current write buffer */ + int write_used; /* number of non-empty write buffers */ + int write_ready; /* write urb is not running */ + spinlock_t write_lock; struct usb_cdc_line_coding line; /* bits, stop, parity */ struct work_struct work; /* work queue entry for line discipline waking up */ struct tasklet_struct bh; /* rx processing */ @@ -71,7 +91,6 @@ struct acm { unsigned int minor; /* acm minor number */ unsigned char throttle; /* throttled by tty layer */ unsigned char clocal; /* termios CLOCAL */ - unsigned char ready_for_write; /* write urb can be used */ unsigned char resubmit_to_unthrottle; /* throtteling has disabled the read urb */ unsigned int ctrl_caps; /* control capabilities from the class specific header */ }; |