Kill rx tasklet, which is no longer needed, and re-write read processing.
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
drivers/usb/class/cdc-acm.c | 292 ++++++++++++++++--------------------------
drivers/usb/class/cdc-acm.h | 22 +---
2 files changed, 117 insertions(+), 197 deletions(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 519c7b9..50d8ce6 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -7,6 +7,7 @@
* Copyright (c) 2000 Vojtech Pavlik <vojtech@xxxxxxx>
* Copyright (c) 2004 Oliver Neukum <oliver@xxxxxxxxxxx>
* Copyright (c) 2005 David Kubicek <dave@xxxxxx>
+ * Copyright (c) 2011 Johan Hovold <jhovold@xxxxxxxxx>
*
* 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 +324,89 @@ 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 && 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 +454,6 @@ 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 +495,11 @@ 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 +527,7 @@ 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 +543,8 @@ 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 +643,31 @@ 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 +805,7 @@ 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 +1066,7 @@ 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 +1095,8 @@ 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 +1105,34 @@ 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 +1217,7 @@ 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 +1236,11 @@ 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 +1301,9 @@ 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 +1365,7 @@ 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 3a895f1..af09c95 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 */
};
--
1.7.4.1
--
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