linux/drivers/usb/class/cdc-acm.h
Jerome Brunet 38203b8385 usb: cdc-acm: fix cooldown mechanism
Commit a4e7279cd1 ("cdc-acm: introduce a cool down") is causing
regression if there is some USB error, such as -EPROTO.

This has been reported on some samples of the Odroid-N2 using the Combee II
Zibgee USB dongle.

> struct acm *acm = container_of(work, struct acm, work)

is incorrect in case of a delayed work and causes warnings, usually from
the workqueue:

> WARNING: CPU: 0 PID: 0 at kernel/workqueue.c:1474 __queue_work+0x480/0x528.

When this happens, USB eventually stops working completely after a while.
Also the ACM_ERROR_DELAY bit is never set, so the cooldown mechanism
previously introduced cannot be triggered and acm_submit_read_urb() is
never called.

This changes makes the cdc-acm driver use a single delayed work, fixing the
pointer arithmetic in acm_softint() and set the ACM_ERROR_DELAY when the
cooldown mechanism appear to be needed.

Fixes: a4e7279cd1 ("cdc-acm: introduce a cool down")
Cc: Oliver Neukum <oneukum@suse.com>
Reported-by: Pascal Vizeli <pascal.vizeli@nabucasa.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20201019170702.150534-1-jbrunet@baylibre.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-28 13:20:21 +01:00

142 lines
3.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
*
* Includes for cdc-acm.c
*
* Mainly take from usbnet's cdc-ether part
*
*/
/*
* CMSPAR, some architectures can't have space and mark parity.
*/
#ifndef CMSPAR
#define CMSPAR 0
#endif
/*
* Major and minor numbers.
*/
#define ACM_TTY_MAJOR 166
#define ACM_TTY_MINORS 256
/*
* Requests.
*/
#define USB_RT_ACM (USB_TYPE_CLASS | USB_RECIP_INTERFACE)
/*
* Output control lines.
*/
#define ACM_CTRL_DTR 0x01
#define ACM_CTRL_RTS 0x02
/*
* Input control lines and line errors.
*/
#define ACM_CTRL_DCD 0x01
#define ACM_CTRL_DSR 0x02
#define ACM_CTRL_BRK 0x04
#define ACM_CTRL_RI 0x08
#define ACM_CTRL_FRAMING 0x10
#define ACM_CTRL_PARITY 0x20
#define ACM_CTRL_OVERRUN 0x40
/*
* Internal driver structures.
*/
/*
* The only reason to have several buffers is to accommodate 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. These values must be
* powers of 2.
*/
#define ACM_NW 16
#define ACM_NR 16
struct acm_wb {
u8 *buf;
dma_addr_t dmah;
unsigned int len;
struct urb *urb;
struct acm *instance;
bool use;
};
struct acm_rb {
int size;
unsigned char *base;
dma_addr_t dma;
int index;
struct acm *instance;
};
struct acm {
struct usb_device *dev; /* the corresponding usb device */
struct usb_interface *control; /* control interface */
struct usb_interface *data; /* data interface */
unsigned in, out; /* i/o pipes */
struct tty_port port; /* our tty port data */
struct urb *ctrlurb; /* urbs */
u8 *ctrl_buffer; /* buffers of urbs */
dma_addr_t ctrl_dma; /* dma handles of buffers */
u8 *country_codes; /* country codes from device */
unsigned int country_code_size; /* size of this buffer */
unsigned int country_rel_date; /* release date of version */
struct acm_wb wb[ACM_NW];
unsigned long read_urbs_free;
struct urb *read_urbs[ACM_NR];
struct acm_rb read_buffers[ACM_NR];
int rx_buflimit;
spinlock_t read_lock;
u8 *notification_buffer; /* to reassemble fragmented notifications */
unsigned int nb_index;
unsigned int nb_size;
int transmitting;
spinlock_t write_lock;
struct mutex mutex;
bool disconnected;
unsigned long flags;
# define EVENT_TTY_WAKEUP 0
# define EVENT_RX_STALL 1
# define ACM_THROTTLED 2
# define ACM_ERROR_DELAY 3
unsigned long urbs_in_error_delay; /* these need to be restarted after a delay */
struct usb_cdc_line_coding line; /* bits, stop, parity */
struct delayed_work dwork; /* work queue entry for various purposes */
unsigned int ctrlin; /* input control lines (DCD, DSR, RI, break, overruns) */
unsigned int ctrlout; /* output control lines (DTR, RTS) */
struct async_icount iocount; /* counters for control line changes */
struct async_icount oldcount; /* for comparison of counter */
wait_queue_head_t wioctl; /* for ioctl */
unsigned int writesize; /* max packet size for the output bulk endpoint */
unsigned int readsize,ctrlsize; /* buffer sizes for freeing */
unsigned int minor; /* acm minor number */
unsigned char clocal; /* termios CLOCAL */
unsigned int ctrl_caps; /* control capabilities from the class specific header */
unsigned int susp_count; /* number of suspended interfaces */
unsigned int combined_interfaces:1; /* control and data collapsed */
u8 bInterval;
struct usb_anchor delayed; /* writes queued for a device about to be woken */
unsigned long quirks;
};
/* constants describing various quirks and errors */
#define NO_UNION_NORMAL BIT(0)
#define SINGLE_RX_URB BIT(1)
#define NO_CAP_LINE BIT(2)
#define IGNORE_DEVICE BIT(3)
#define QUIRK_CONTROL_LINE_STATE BIT(4)
#define CLEAR_HALT_CONDITIONS BIT(5)
#define SEND_ZERO_PACKET BIT(6)
#define DISABLE_ECHO BIT(7)