diff options
author | Michał Mirosław <mirq-linux@rere.qmqm.pl> | 2019-08-10 10:42:49 +0200 |
---|---|---|
committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2019-10-22 09:27:06 +0200 |
commit | fe1ea63ad8064d8518b5e3fd1a6869b4463b5c73 (patch) | |
tree | 400cb93195d313fa1aec49da51c2818798c17bb2 /drivers/usb/gadget/function | |
parent | usb: gadget: u_serial: add missing port entry locking (diff) | |
download | linux-fe1ea63ad8064d8518b5e3fd1a6869b4463b5c73.tar.xz linux-fe1ea63ad8064d8518b5e3fd1a6869b4463b5c73.zip |
usb: gadget: u_serial: reimplement console support
Rewrite console support to fix a few shortcomings of the old code
preventing its use with multiple ports. This removes some duplicated
code and replaces a custom kthread with simpler workqueue item.
Only port ttyGS0 gets to be a console for now.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb/gadget/function')
-rw-r--r-- | drivers/usb/gadget/function/u_serial.c | 339 |
1 files changed, 158 insertions, 181 deletions
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index bb1e2e1d0076..94f6999e8262 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -82,14 +82,12 @@ #define GS_CONSOLE_BUF_SIZE 8192 /* console info */ -struct gscons_info { - struct gs_port *port; - struct task_struct *console_thread; - struct kfifo con_buf; - /* protect the buf and busy flag */ - spinlock_t con_lock; - int req_busy; - struct usb_request *console_req; +struct gs_console { + struct console console; + struct work_struct work; + spinlock_t lock; + struct usb_request *req; + struct kfifo buf; }; /* @@ -101,6 +99,9 @@ struct gs_port { spinlock_t port_lock; /* guard port_* access */ struct gserial *port_usb; +#ifdef CONFIG_U_SERIAL_CONSOLE + struct gs_console *console; +#endif bool openclose; /* open/close in progress */ u8 port_num; @@ -889,36 +890,9 @@ static struct tty_driver *gs_tty_driver; #ifdef CONFIG_U_SERIAL_CONSOLE -static struct gscons_info gscons_info; -static struct console gserial_cons; - -static struct usb_request *gs_request_new(struct usb_ep *ep) +static void gs_console_complete_out(struct usb_ep *ep, struct usb_request *req) { - struct usb_request *req = usb_ep_alloc_request(ep, GFP_ATOMIC); - if (!req) - return NULL; - - req->buf = kmalloc(ep->maxpacket, GFP_ATOMIC); - if (!req->buf) { - usb_ep_free_request(ep, req); - return NULL; - } - - return req; -} - -static void gs_request_free(struct usb_request *req, struct usb_ep *ep) -{ - if (!req) - return; - - kfree(req->buf); - usb_ep_free_request(ep, req); -} - -static void gs_complete_out(struct usb_ep *ep, struct usb_request *req) -{ - struct gscons_info *info = &gscons_info; + struct gs_console *cons = req->context; switch (req->status) { default: @@ -927,12 +901,12 @@ static void gs_complete_out(struct usb_ep *ep, struct usb_request *req) /* fall through */ case 0: /* normal completion */ - spin_lock(&info->con_lock); - info->req_busy = 0; - spin_unlock(&info->con_lock); - - wake_up_process(info->console_thread); + spin_lock(&cons->lock); + req->length = 0; + schedule_work(&cons->work); + spin_unlock(&cons->lock); break; + case -ECONNRESET: case -ESHUTDOWN: /* disconnect */ pr_vdebug("%s: %s shutdown\n", __func__, ep->name); @@ -940,190 +914,190 @@ static void gs_complete_out(struct usb_ep *ep, struct usb_request *req) } } -static int gs_console_connect(int port_num) +static void __gs_console_push(struct gs_console *cons) { - struct gscons_info *info = &gscons_info; - struct gs_port *port; + struct usb_request *req = cons->req; struct usb_ep *ep; + size_t size; - if (port_num != gserial_cons.index) { - pr_err("%s: port num [%d] is not support console\n", - __func__, port_num); - return -ENXIO; - } + if (!req) + return; /* disconnected */ - port = ports[port_num].port; - ep = port->port_usb->in; - if (!info->console_req) { - info->console_req = gs_request_new(ep); - if (!info->console_req) - return -ENOMEM; - info->console_req->complete = gs_complete_out; - } + if (req->length) + return; /* busy */ - info->port = port; - spin_lock(&info->con_lock); - info->req_busy = 0; - spin_unlock(&info->con_lock); - pr_vdebug("port[%d] console connect!\n", port_num); - return 0; + ep = cons->console.data; + size = kfifo_out(&cons->buf, req->buf, ep->maxpacket); + if (!size) + return; + + req->length = size; + if (usb_ep_queue(ep, req, GFP_ATOMIC)) + req->length = 0; } -static void gs_console_disconnect(struct usb_ep *ep) +static void gs_console_work(struct work_struct *work) { - struct gscons_info *info = &gscons_info; - struct usb_request *req = info->console_req; + struct gs_console *cons = container_of(work, struct gs_console, work); + + spin_lock_irq(&cons->lock); - gs_request_free(req, ep); - info->console_req = NULL; + __gs_console_push(cons); + + spin_unlock_irq(&cons->lock); } -static int gs_console_thread(void *data) +static void gs_console_write(struct console *co, + const char *buf, unsigned count) { - struct gscons_info *info = &gscons_info; - struct gs_port *port; - struct usb_request *req; - struct usb_ep *ep; - int xfer, ret, count, size; + struct gs_console *cons = container_of(co, struct gs_console, console); + unsigned long flags; - do { - port = info->port; - set_current_state(TASK_INTERRUPTIBLE); - if (!port || !port->port_usb - || !port->port_usb->in || !info->console_req) - goto sched; - - req = info->console_req; - ep = port->port_usb->in; - - spin_lock_irq(&info->con_lock); - count = kfifo_len(&info->con_buf); - size = ep->maxpacket; - - if (count > 0 && !info->req_busy) { - set_current_state(TASK_RUNNING); - if (count < size) - size = count; - - xfer = kfifo_out(&info->con_buf, req->buf, size); - req->length = xfer; - - spin_unlock(&info->con_lock); - ret = usb_ep_queue(ep, req, GFP_ATOMIC); - spin_lock(&info->con_lock); - if (ret < 0) - info->req_busy = 0; - else - info->req_busy = 1; - - spin_unlock_irq(&info->con_lock); - } else { - spin_unlock_irq(&info->con_lock); -sched: - if (kthread_should_stop()) { - set_current_state(TASK_RUNNING); - break; - } - schedule(); - } - } while (1); + spin_lock_irqsave(&cons->lock, flags); - return 0; + kfifo_in(&cons->buf, buf, count); + + if (cons->req && !cons->req->length) + schedule_work(&cons->work); + + spin_unlock_irqrestore(&cons->lock, flags); } -static int gs_console_setup(struct console *co, char *options) +static struct tty_driver *gs_console_device(struct console *co, int *index) { - struct gscons_info *info = &gscons_info; - int status; + *index = co->index; + return gs_tty_driver; +} - info->port = NULL; - info->console_req = NULL; - info->req_busy = 0; - spin_lock_init(&info->con_lock); +static int gs_console_connect(struct gs_port *port) +{ + struct gs_console *cons = port->console; + struct usb_request *req; + struct usb_ep *ep; - status = kfifo_alloc(&info->con_buf, GS_CONSOLE_BUF_SIZE, GFP_KERNEL); - if (status) { - pr_err("%s: allocate console buffer failed\n", __func__); - return status; - } + if (!cons) + return 0; - info->console_thread = kthread_create(gs_console_thread, - co, "gs_console"); - if (IS_ERR(info->console_thread)) { - pr_err("%s: cannot create console thread\n", __func__); - kfifo_free(&info->con_buf); - return PTR_ERR(info->console_thread); - } - wake_up_process(info->console_thread); + ep = port->port_usb->in; + req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC); + if (!req) + return -ENOMEM; + req->complete = gs_console_complete_out; + req->context = cons; + req->length = 0; + + spin_lock(&cons->lock); + cons->req = req; + cons->console.data = ep; + spin_unlock(&cons->lock); + + pr_debug("ttyGS%d: console connected!\n", port->port_num); + + schedule_work(&cons->work); return 0; } -static void gs_console_write(struct console *co, - const char *buf, unsigned count) +static void gs_console_disconnect(struct gs_port *port) { - struct gscons_info *info = &gscons_info; - unsigned long flags; + struct gs_console *cons = port->console; + struct usb_request *req; + struct usb_ep *ep; + + if (!cons) + return; - spin_lock_irqsave(&info->con_lock, flags); - kfifo_in(&info->con_buf, buf, count); - spin_unlock_irqrestore(&info->con_lock, flags); + spin_lock(&cons->lock); - wake_up_process(info->console_thread); + req = cons->req; + ep = cons->console.data; + cons->req = NULL; + + spin_unlock(&cons->lock); + + if (!req) + return; + + usb_ep_dequeue(ep, req); + gs_free_req(ep, req); } -static struct tty_driver *gs_console_device(struct console *co, int *index) +static int gs_console_init(struct gs_port *port) { - struct tty_driver **p = (struct tty_driver **)co->data; + struct gs_console *cons; + int err; - if (!*p) - return NULL; + if (port->console) + return 0; - *index = co->index; - return *p; -} + cons = kzalloc(sizeof(*port->console), GFP_KERNEL); + if (!cons) + return -ENOMEM; -static struct console gserial_cons = { - .name = "ttyGS", - .write = gs_console_write, - .device = gs_console_device, - .setup = gs_console_setup, - .flags = CON_PRINTBUFFER, - .index = -1, - .data = &gs_tty_driver, -}; + strcpy(cons->console.name, "ttyGS"); + cons->console.write = gs_console_write; + cons->console.device = gs_console_device; + cons->console.flags = CON_PRINTBUFFER; + cons->console.index = port->port_num; -static void gserial_console_init(void) -{ - register_console(&gserial_cons); + INIT_WORK(&cons->work, gs_console_work); + spin_lock_init(&cons->lock); + + err = kfifo_alloc(&cons->buf, GS_CONSOLE_BUF_SIZE, GFP_KERNEL); + if (err) { + pr_err("ttyGS%d: allocate console buffer failed\n", port->port_num); + kfree(cons); + return err; + } + + port->console = cons; + register_console(&cons->console); + + spin_lock_irq(&port->port_lock); + if (port->port_usb) + gs_console_connect(port); + spin_unlock_irq(&port->port_lock); + + return 0; } -static void gserial_console_exit(void) +static void gs_console_exit(struct gs_port *port) { - struct gscons_info *info = &gscons_info; + struct gs_console *cons = port->console; + + if (!cons) + return; + + unregister_console(&cons->console); + + spin_lock_irq(&port->port_lock); + if (cons->req) + gs_console_disconnect(port); + spin_unlock_irq(&port->port_lock); - unregister_console(&gserial_cons); - if (!IS_ERR_OR_NULL(info->console_thread)) - kthread_stop(info->console_thread); - kfifo_free(&info->con_buf); + cancel_work_sync(&cons->work); + kfifo_free(&cons->buf); + kfree(cons); + port->console = NULL; } #else -static int gs_console_connect(int port_num) +static int gs_console_connect(struct gs_port *port) { return 0; } -static void gs_console_disconnect(struct usb_ep *ep) +static void gs_console_disconnect(struct gs_port *port) { } -static void gserial_console_init(void) +static int gs_console_init(struct gs_port *port) { + return -ENOSYS; } -static void gserial_console_exit(void) +static void gs_console_exit(struct gs_port *port) { } @@ -1197,18 +1171,19 @@ void gserial_free_line(unsigned char port_num) return; } port = ports[port_num].port; + gs_console_exit(port); ports[port_num].port = NULL; mutex_unlock(&ports[port_num].lock); gserial_free_port(port); tty_unregister_device(gs_tty_driver, port_num); - gserial_console_exit(); } EXPORT_SYMBOL_GPL(gserial_free_line); int gserial_alloc_line(unsigned char *line_num) { struct usb_cdc_line_coding coding; + struct gs_port *port; struct device *tty_dev; int ret; int port_num; @@ -1231,23 +1206,24 @@ int gserial_alloc_line(unsigned char *line_num) /* ... and sysfs class devices, so mdev/udev make /dev/ttyGS* */ - tty_dev = tty_port_register_device(&ports[port_num].port->port, + port = ports[port_num].port; + tty_dev = tty_port_register_device(&port->port, gs_tty_driver, port_num, NULL); if (IS_ERR(tty_dev)) { - struct gs_port *port; pr_err("%s: failed to register tty for port %d, err %ld\n", __func__, port_num, PTR_ERR(tty_dev)); ret = PTR_ERR(tty_dev); mutex_lock(&ports[port_num].lock); - port = ports[port_num].port; ports[port_num].port = NULL; mutex_unlock(&ports[port_num].lock); gserial_free_port(port); goto err; } *line_num = port_num; - gserial_console_init(); + + if (!port_num) + gs_console_init(port); err: return ret; } @@ -1329,7 +1305,7 @@ int gserial_connect(struct gserial *gser, u8 port_num) gser->disconnect(gser); } - status = gs_console_connect(port_num); + status = gs_console_connect(port); spin_unlock_irqrestore(&port->port_lock, flags); return status; @@ -1361,6 +1337,8 @@ void gserial_disconnect(struct gserial *gser) /* tell the TTY glue not to do I/O here any more */ spin_lock_irqsave(&port->port_lock, flags); + gs_console_disconnect(port); + /* REVISIT as above: how best to track this? */ port->port_line_coding = gser->port_line_coding; @@ -1388,7 +1366,6 @@ void gserial_disconnect(struct gserial *gser) port->read_allocated = port->read_started = port->write_allocated = port->write_started = 0; - gs_console_disconnect(gser->in); spin_unlock_irqrestore(&port->port_lock, flags); } EXPORT_SYMBOL_GPL(gserial_disconnect); |