From 088c64f812847b3623b03d167ed329f90f3e38a4 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 25 Mar 2011 11:06:02 +0100 Subject: [PATCH] USB: cdc-acm: re-write read processing Kill rx tasklet, which is no longer needed, and re-write read processing. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 295 ++++++++++++++---------------------- drivers/usb/class/cdc-acm.h | 22 +-- 2 files changed, 120 insertions(+), 197 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 519c7b933508..58754b508a0f 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -7,6 +7,7 @@ * Copyright (c) 2000 Vojtech Pavlik * Copyright (c) 2004 Oliver Neukum * Copyright (c) 2005 David Kubicek + * Copyright (c) 2011 Johan Hovold * * USB Abstract Control Model driver for USB modems and ISDN adapters * @@ -50,7 +51,7 @@ #include "cdc-acm.h" -#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek" +#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek, Johan Hovold" #define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters" static struct usb_driver acm_driver; @@ -323,166 +324,92 @@ exit: __func__, retval); } -/* data interface returns incoming bytes, or we got unthrottled */ -static void acm_read_bulk(struct urb *urb) +static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags) { - struct acm_rb *buf; - struct acm_ru *rcv = urb->context; - struct acm *acm = rcv->instance; - int status = urb->status; + int res; - dev_vdbg(&acm->data->dev, "%s - status %d\n", __func__, status); + if (!test_and_clear_bit(index, &acm->read_urbs_free)) + return 0; - if (!ACM_READY(acm)) { - dev_dbg(&acm->data->dev, "%s - acm not ready\n", __func__); - return; + dev_vdbg(&acm->data->dev, "%s - urb %d\n", __func__, index); + + res = usb_submit_urb(acm->read_urbs[index], mem_flags); + if (res) { + if (res != -EPERM) { + dev_err(&acm->data->dev, + "%s - usb_submit_urb failed: %d\n", + __func__, res); + } + set_bit(index, &acm->read_urbs_free); + return res; } - usb_mark_last_busy(acm->dev); - if (status) - dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n", - __func__, status); + return 0; +} - buf = rcv->buffer; - buf->size = urb->actual_length; +static int acm_submit_read_urbs(struct acm *acm, gfp_t mem_flags) +{ + int res; + int i; - if (likely(status == 0)) { - spin_lock(&acm->read_lock); - acm->processing++; - list_add_tail(&rcv->list, &acm->spare_read_urbs); - list_add_tail(&buf->list, &acm->filled_read_bufs); - spin_unlock(&acm->read_lock); - } else { - /* we drop the buffer due to an error */ - spin_lock(&acm->read_lock); - list_add_tail(&rcv->list, &acm->spare_read_urbs); - list_add(&buf->list, &acm->spare_read_bufs); - spin_unlock(&acm->read_lock); - /* nevertheless the tasklet must be kicked unconditionally - so the queue cannot dry up */ + for (i = 0; i < acm->rx_buflimit; ++i) { + res = acm_submit_read_urb(acm, i, mem_flags); + if (res) + return res; } - if (likely(!acm->susp_count)) - tasklet_schedule(&acm->urb_task); + + return 0; } -static void acm_rx_tasklet(unsigned long _acm) +static void acm_process_read_urb(struct acm *acm, struct urb *urb) { - struct acm *acm = (void *)_acm; - struct acm_rb *buf; struct tty_struct *tty; - struct acm_ru *rcv; - unsigned long flags; - unsigned char throttled; - - dev_vdbg(&acm->data->dev, "%s\n", __func__); - if (!ACM_READY(acm)) { - dev_dbg(&acm->data->dev, "%s - acm not ready\n", __func__); + if (!urb->actual_length) return; - } - - spin_lock_irqsave(&acm->throttle_lock, flags); - throttled = acm->throttle; - spin_unlock_irqrestore(&acm->throttle_lock, flags); - if (throttled) { - dev_dbg(&acm->data->dev, "%s - throttled\n", __func__); - return; - } tty = tty_port_tty_get(&acm->port); + if (!tty) + return; -next_buffer: - spin_lock_irqsave(&acm->read_lock, flags); - if (list_empty(&acm->filled_read_bufs)) { - spin_unlock_irqrestore(&acm->read_lock, flags); - goto urbs; - } - buf = list_entry(acm->filled_read_bufs.next, - struct acm_rb, list); - list_del(&buf->list); - spin_unlock_irqrestore(&acm->read_lock, flags); - - dev_vdbg(&acm->data->dev, "%s - processing buf 0x%p, size = %d\n", - __func__, buf, buf->size); - if (tty) { - spin_lock_irqsave(&acm->throttle_lock, flags); - throttled = acm->throttle; - spin_unlock_irqrestore(&acm->throttle_lock, flags); - if (!throttled) { - tty_insert_flip_string(tty, buf->base, buf->size); - tty_flip_buffer_push(tty); - } else { - tty_kref_put(tty); - dev_dbg(&acm->data->dev, "%s - throttling noticed\n", - __func__); - spin_lock_irqsave(&acm->read_lock, flags); - list_add(&buf->list, &acm->filled_read_bufs); - spin_unlock_irqrestore(&acm->read_lock, flags); - return; - } - } - - spin_lock_irqsave(&acm->read_lock, flags); - list_add(&buf->list, &acm->spare_read_bufs); - spin_unlock_irqrestore(&acm->read_lock, flags); - goto next_buffer; + tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length); + tty_flip_buffer_push(tty); -urbs: tty_kref_put(tty); +} - while (!list_empty(&acm->spare_read_bufs)) { - spin_lock_irqsave(&acm->read_lock, flags); - if (list_empty(&acm->spare_read_urbs)) { - acm->processing = 0; - spin_unlock_irqrestore(&acm->read_lock, flags); - return; - } - rcv = list_entry(acm->spare_read_urbs.next, - struct acm_ru, list); - list_del(&rcv->list); - spin_unlock_irqrestore(&acm->read_lock, flags); +static void acm_read_bulk_callback(struct urb *urb) +{ + struct acm_rb *rb = urb->context; + struct acm *acm = rb->instance; + unsigned long flags; - buf = list_entry(acm->spare_read_bufs.next, - struct acm_rb, list); - list_del(&buf->list); + dev_vdbg(&acm->data->dev, "%s - urb %d, len %d\n", __func__, + rb->index, urb->actual_length); + set_bit(rb->index, &acm->read_urbs_free); - rcv->buffer = buf; + if (!acm->dev) { + dev_dbg(&acm->data->dev, "%s - disconnected\n", __func__); + return; + } + usb_mark_last_busy(acm->dev); - if (acm->is_int_ep) - usb_fill_int_urb(rcv->urb, acm->dev, - acm->rx_endpoint, - buf->base, - acm->readsize, - acm_read_bulk, rcv, acm->bInterval); - else - usb_fill_bulk_urb(rcv->urb, acm->dev, - acm->rx_endpoint, - buf->base, - acm->readsize, - acm_read_bulk, rcv); - rcv->urb->transfer_dma = buf->dma; - rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; - - /* This shouldn't kill the driver as unsuccessful URBs are - returned to the free-urbs-pool and resubmited ASAP */ - spin_lock_irqsave(&acm->read_lock, flags); - if (acm->susp_count || - usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) { - list_add(&buf->list, &acm->spare_read_bufs); - list_add(&rcv->list, &acm->spare_read_urbs); - acm->processing = 0; - spin_unlock_irqrestore(&acm->read_lock, flags); - return; - } else { - spin_unlock_irqrestore(&acm->read_lock, flags); - dev_vdbg(&acm->data->dev, - "%s - sending urb 0x%p, rcv 0x%p, buf 0x%p\n", - __func__, rcv->urb, rcv, buf); - } + if (urb->status) { + dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n", + __func__, urb->status); + return; } + acm_process_read_urb(acm, urb); + + /* throttle device if requested by tty */ spin_lock_irqsave(&acm->read_lock, flags); - acm->processing = 0; - spin_unlock_irqrestore(&acm->read_lock, flags); + acm->throttled = acm->throttle_req; + if (!acm->throttled && !acm->susp_count) { + spin_unlock_irqrestore(&acm->read_lock, flags); + acm_submit_read_urb(acm, rb->index, GFP_ATOMIC); + } else { + spin_unlock_irqrestore(&acm->read_lock, flags); + } } /* data interface wrote those outgoing bytes */ @@ -530,7 +457,6 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) { struct acm *acm; int rv = -ENODEV; - int i; mutex_lock(&open_mutex); @@ -572,20 +498,11 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) usb_autopm_put_interface(acm->control); - INIT_LIST_HEAD(&acm->spare_read_urbs); - INIT_LIST_HEAD(&acm->spare_read_bufs); - INIT_LIST_HEAD(&acm->filled_read_bufs); - - for (i = 0; i < acm->rx_buflimit; i++) - list_add(&(acm->ru[i].list), &acm->spare_read_urbs); - for (i = 0; i < acm->rx_buflimit; i++) - list_add(&(acm->rb[i].list), &acm->spare_read_bufs); - - acm->throttle = 0; + if (acm_submit_read_urbs(acm, GFP_KERNEL)) + goto bail_out; set_bit(ASYNCB_INITIALIZED, &acm->port.flags); rv = tty_port_block_til_ready(&acm->port, tty, filp); - tasklet_schedule(&acm->urb_task); mutex_unlock(&acm->mutex); out: @@ -613,7 +530,7 @@ static void acm_tty_unregister(struct acm *acm) for (i = 0; i < ACM_NW; i++) usb_free_urb(acm->wb[i].urb); for (i = 0; i < acm->rx_buflimit; i++) - usb_free_urb(acm->ru[i].urb); + usb_free_urb(acm->read_urbs[i]); kfree(acm->country_codes); kfree(acm); } @@ -629,10 +546,8 @@ static void acm_port_down(struct acm *acm) usb_kill_urb(acm->ctrlurb); for (i = 0; i < ACM_NW; i++) usb_kill_urb(acm->wb[i].urb); - tasklet_disable(&acm->urb_task); for (i = 0; i < acm->rx_buflimit; i++) - usb_kill_urb(acm->ru[i].urb); - tasklet_enable(&acm->urb_task); + usb_kill_urb(acm->read_urbs[i]); acm->control->needs_remote_wakeup = 0; usb_autopm_put_interface(acm->control); } @@ -731,22 +646,31 @@ static int acm_tty_chars_in_buffer(struct tty_struct *tty) static void acm_tty_throttle(struct tty_struct *tty) { struct acm *acm = tty->driver_data; + if (!ACM_READY(acm)) return; - spin_lock_bh(&acm->throttle_lock); - acm->throttle = 1; - spin_unlock_bh(&acm->throttle_lock); + + spin_lock_irq(&acm->read_lock); + acm->throttle_req = 1; + spin_unlock_irq(&acm->read_lock); } static void acm_tty_unthrottle(struct tty_struct *tty) { struct acm *acm = tty->driver_data; + unsigned int was_throttled; + if (!ACM_READY(acm)) return; - spin_lock_bh(&acm->throttle_lock); - acm->throttle = 0; - spin_unlock_bh(&acm->throttle_lock); - tasklet_schedule(&acm->urb_task); + + spin_lock_irq(&acm->read_lock); + was_throttled = acm->throttled; + acm->throttled = 0; + acm->throttle_req = 0; + spin_unlock_irq(&acm->read_lock); + + if (was_throttled) + acm_submit_read_urbs(acm, GFP_KERNEL); } static int acm_tty_break_ctl(struct tty_struct *tty, int state) @@ -884,7 +808,7 @@ static void acm_read_buffers_free(struct acm *acm) for (i = 0; i < acm->rx_buflimit; i++) usb_free_coherent(usb_dev, acm->readsize, - acm->rb[i].base, acm->rb[i].dma); + acm->read_buffers[i].base, acm->read_buffers[i].dma); } /* Little helper: write buffers allocate */ @@ -1145,10 +1069,7 @@ made_compressed_probe: acm->ctrlsize = ctrlsize; acm->readsize = readsize; acm->rx_buflimit = num_rx_buf; - acm->urb_task.func = acm_rx_tasklet; - acm->urb_task.data = (unsigned long) acm; INIT_WORK(&acm->work, acm_softint); - spin_lock_init(&acm->throttle_lock); spin_lock_init(&acm->write_lock); spin_lock_init(&acm->read_lock); mutex_init(&acm->mutex); @@ -1177,8 +1098,8 @@ made_compressed_probe: goto alloc_fail5; } for (i = 0; i < num_rx_buf; i++) { - struct acm_rb *rb = &(acm->rb[i]); - struct acm_ru *rcv = &(acm->ru[i]); + struct acm_rb *rb = &(acm->read_buffers[i]); + struct urb *urb; rb->base = usb_alloc_coherent(acm->dev, readsize, GFP_KERNEL, &rb->dma); @@ -1187,16 +1108,34 @@ made_compressed_probe: "(read bufs usb_alloc_coherent)\n"); goto alloc_fail6; } + rb->index = i; + rb->instance = acm; - rcv->urb = usb_alloc_urb(0, GFP_KERNEL); - if (rcv->urb == NULL) { + urb = usb_alloc_urb(0, GFP_KERNEL); + if (!urb) { dev_err(&intf->dev, "out of memory (read urbs usb_alloc_urb)\n"); goto alloc_fail6; } + urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; + urb->transfer_dma = rb->dma; + if (acm->is_int_ep) { + usb_fill_int_urb(urb, acm->dev, + acm->rx_endpoint, + rb->base, + acm->readsize, + acm_read_bulk_callback, rb, + acm->bInterval); + } else { + usb_fill_bulk_urb(urb, acm->dev, + acm->rx_endpoint, + rb->base, + acm->readsize, + acm_read_bulk_callback, rb); + } - rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; - rcv->instance = acm; + acm->read_urbs[i] = urb; + __set_bit(i, &acm->read_urbs_free); } for (i = 0; i < ACM_NW; i++) { struct acm_wb *snd = &(acm->wb[i]); @@ -1281,7 +1220,7 @@ alloc_fail7: usb_free_urb(acm->wb[i].urb); alloc_fail6: for (i = 0; i < num_rx_buf; i++) - usb_free_urb(acm->ru[i].urb); + usb_free_urb(acm->read_urbs[i]); acm_read_buffers_free(acm); usb_free_urb(acm->ctrlurb); alloc_fail5: @@ -1300,15 +1239,11 @@ static void stop_data_traffic(struct acm *acm) dev_dbg(&acm->control->dev, "%s\n", __func__); - tasklet_disable(&acm->urb_task); - usb_kill_urb(acm->ctrlurb); for (i = 0; i < ACM_NW; i++) usb_kill_urb(acm->wb[i].urb); for (i = 0; i < acm->rx_buflimit; i++) - usb_kill_urb(acm->ru[i].urb); - - tasklet_enable(&acm->urb_task); + usb_kill_urb(acm->read_urbs[i]); cancel_work_sync(&acm->work); } @@ -1369,11 +1304,9 @@ static int acm_suspend(struct usb_interface *intf, pm_message_t message) if (message.event & PM_EVENT_AUTO) { int b; - spin_lock_irq(&acm->read_lock); - spin_lock(&acm->write_lock); - b = acm->processing + acm->transmitting; - spin_unlock(&acm->write_lock); - spin_unlock_irq(&acm->read_lock); + spin_lock_irq(&acm->write_lock); + b = acm->transmitting; + spin_unlock_irq(&acm->write_lock); if (b) return -EBUSY; } @@ -1435,7 +1368,7 @@ static int acm_resume(struct usb_interface *intf) if (rv < 0) goto err_out; - tasklet_schedule(&acm->urb_task); + rv = acm_submit_read_urbs(acm, GFP_NOIO); } err_out: diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h index 7282d1f4912b..7b5c0bd07f80 100644 --- a/drivers/usb/class/cdc-acm.h +++ b/drivers/usb/class/cdc-acm.h @@ -72,16 +72,10 @@ struct acm_wb { }; struct acm_rb { - struct list_head list; int size; unsigned char *base; dma_addr_t dma; -}; - -struct acm_ru { - struct list_head list; - struct acm_rb *buffer; - struct urb *urb; + int index; struct acm *instance; }; @@ -97,34 +91,30 @@ struct acm { unsigned int country_code_size; /* size of this buffer */ unsigned int country_rel_date; /* release date of version */ struct acm_wb wb[ACM_NW]; - struct acm_ru ru[ACM_NR]; - struct acm_rb rb[ACM_NR]; + unsigned long read_urbs_free; + struct urb *read_urbs[ACM_NR]; + struct acm_rb read_buffers[ACM_NR]; int rx_buflimit; int rx_endpoint; spinlock_t read_lock; - struct list_head spare_read_urbs; - struct list_head spare_read_bufs; - struct list_head filled_read_bufs; int write_used; /* number of non-empty write buffers */ - int processing; int transmitting; spinlock_t write_lock; struct mutex mutex; struct usb_cdc_line_coding line; /* bits, stop, parity */ struct work_struct work; /* work queue entry for line discipline waking up */ - struct tasklet_struct urb_task; /* rx processing */ - spinlock_t throttle_lock; /* synchronize throtteling and read callback */ unsigned int ctrlin; /* input control lines (DCD, DSR, RI, break, overruns) */ unsigned int ctrlout; /* output control lines (DTR, RTS) */ 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 throttle; /* throttled by tty layer */ 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 */ unsigned int is_int_ep:1; /* interrupt endpoints contrary to spec used */ + unsigned int throttled:1; /* actually throttled */ + unsigned int throttle_req:1; /* throttle requested */ u8 bInterval; struct acm_wb *delayed_wb; /* write queued for a device about to be woken */ }; -- 2.20.1