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OpenCloudOS-Kernel
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staging: most: i2c: remove redundant list_mutex 

The elements of the dev->rx.list are consumed in the pending_rx_work and
populated in the function enqueue() that cancels the pending_rx_work.

The function enqueue() and poison_channel() do not race anyway.

Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christian Gromm 2018-05-08 11:45:01 +02:00 committed by Greg Kroah-Hartman
parent 6471c2693f
commit eb50842c5f
1 changed files with 1 additions and 16 deletions
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17
drivers/staging/most/i2c/i2c.c
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@ -46,7 +46,6 @@ struct hdm_i2c {
struct rx {
struct delayed_work dwork;
struct list_head list;
struct mutex list_mutex;
bool int_disabled;
unsigned int delay;
} rx;
@ -139,9 +138,7 @@ static int enqueue(struct most_interface *most_iface,
if (!dev->polling_mode)
disable_irq(dev->client->irq);
cancel_delayed_work_sync(&dev->rx.dwork);
mutex_lock(&dev->rx.list_mutex);
list_add_tail(&mbo->list, &dev->rx.list);
mutex_unlock(&dev->rx.list_mutex);
if (dev->rx.int_disabled || dev->polling_mode)
pending_rx_work(&dev->rx.dwork.work);
if (!dev->polling_mode)
@ -186,19 +183,14 @@ static int poison_channel(struct most_interface *most_iface,
free_irq(dev->client->irq, dev);
cancel_delayed_work_sync(&dev->rx.dwork);
mutex_lock(&dev->rx.list_mutex);
while (!list_empty(&dev->rx.list)) {
mbo = list_first_mbo(&dev->rx.list);
list_del(&mbo->list);
mutex_unlock(&dev->rx.list_mutex);
mbo->processed_length = 0;
mbo->status = MBO_E_CLOSE;
mbo->complete(mbo);
mutex_lock(&dev->rx.list_mutex);
}
mutex_unlock(&dev->rx.list_mutex);
}
return 0;
@ -231,10 +223,8 @@ static void do_rx_work(struct hdm_i2c *dev)
return;
}
mutex_lock(&dev->rx.list_mutex);
mbo = list_first_mbo(&dev->rx.list);
list_del(&mbo->list);
mutex_unlock(&dev->rx.list_mutex);
mbo->processed_length = min(data_size, mbo->buffer_length);
memcpy(mbo->virt_address, msg, mbo->processed_length);
@ -251,12 +241,8 @@ static void do_rx_work(struct hdm_i2c *dev)
static void pending_rx_work(struct work_struct *work)
{
struct hdm_i2c *dev = container_of(work, struct hdm_i2c, rx.dwork.work);
bool empty;
mutex_lock(&dev->rx.list_mutex);
empty = list_empty(&dev->rx.list);
mutex_unlock(&dev->rx.list_mutex);
if (empty)
if (list_empty(&dev->rx.list))
return;
do_rx_work(dev);
@ -340,7 +326,6 @@ static int i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
dev->most_iface.poison_channel = poison_channel;
INIT_LIST_HEAD(&dev->rx.list);
mutex_init(&dev->rx.list_mutex);
INIT_DELAYED_WORK(&dev->rx.dwork, pending_rx_work);