* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
struct spi_transfer *xfer;
bool keep_cs = false;
int ret = 0;
- int ms = 1;
+ unsigned long ms = 1;
spi_set_cs(msg->spi, true);
EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
/**
- * spi_pump_messages - kthread work function which processes spi message queue
- * @work: pointer to kthread work struct contained in the master struct
+ * __spi_pump_messages - function which processes spi message queue
+ * @master: master to process queue for
+ * @in_kthread: true if we are in the context of the message pump thread
*
* This function checks if there is any spi message in the queue that
* needs processing and if so call out to the driver to initialize hardware
* and transfer each message.
*
+ * Note that it is called both from the kthread itself and also from
+ * inside spi_sync(); the queue extraction handling at the top of the
+ * function should deal with this safely.
*/
-static void spi_pump_messages(struct kthread_work *work)
+static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
{
- struct spi_master *master =
- container_of(work, struct spi_master, pump_messages);
unsigned long flags;
bool was_busy = false;
int ret;
- /* Lock queue and check for queue work */
+ /* Lock queue */
spin_lock_irqsave(&master->queue_lock, flags);
+
+ /* Make sure we are not already running a message */
+ if (master->cur_msg) {
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+
+ /* If another context is idling the device then defer */
+ if (master->idling) {
+ queue_kthread_work(&master->kworker, &master->pump_messages);
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+
+ /* Check if the queue is idle */
if (list_empty(&master->queue) || !master->running) {
if (!master->busy) {
spin_unlock_irqrestore(&master->queue_lock, flags);
return;
}
+
+ /* Only do teardown in the thread */
+ if (!in_kthread) {
+ queue_kthread_work(&master->kworker,
+ &master->pump_messages);
+ spin_unlock_irqrestore(&master->queue_lock, flags);
+ return;
+ }
+
master->busy = false;
+ master->idling = true;
spin_unlock_irqrestore(&master->queue_lock, flags);
+
kfree(master->dummy_rx);
master->dummy_rx = NULL;
kfree(master->dummy_tx);
pm_runtime_put_autosuspend(master->dev.parent);
}
trace_spi_master_idle(master);
- return;
- }
- /* Make sure we are not already running a message */
- if (master->cur_msg) {
+ spin_lock_irqsave(&master->queue_lock, flags);
+ master->idling = false;
spin_unlock_irqrestore(&master->queue_lock, flags);
return;
}
+
/* Extract head of queue */
master->cur_msg =
list_first_entry(&master->queue, struct spi_message, queue);
}
}
+/**
+ * spi_pump_messages - kthread work function which processes spi message queue
+ * @work: pointer to kthread work struct contained in the master struct
+ */
+static void spi_pump_messages(struct kthread_work *work)
+{
+ struct spi_master *master =
+ container_of(work, struct spi_master, pump_messages);
+
+ __spi_pump_messages(master, true);
+}
+
static int spi_init_queue(struct spi_master *master)
{
struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
- INIT_LIST_HEAD(&master->queue);
- spin_lock_init(&master->queue_lock);
-
master->running = false;
master->busy = false;
return 0;
}
-/**
- * spi_queued_transfer - transfer function for queued transfers
- * @spi: spi device which is requesting transfer
- * @msg: spi message which is to handled is queued to driver queue
- */
-static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
+static int __spi_queued_transfer(struct spi_device *spi,
+ struct spi_message *msg,
+ bool need_pump)
{
struct spi_master *master = spi->master;
unsigned long flags;
msg->status = -EINPROGRESS;
list_add_tail(&msg->queue, &master->queue);
- if (!master->busy)
+ if (!master->busy && need_pump)
queue_kthread_work(&master->kworker, &master->pump_messages);
spin_unlock_irqrestore(&master->queue_lock, flags);
return 0;
}
+/**
+ * spi_queued_transfer - transfer function for queued transfers
+ * @spi: spi device which is requesting transfer
+ * @msg: spi message which is to handled is queued to driver queue
+ */
+static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ return __spi_queued_transfer(spi, msg, true);
+}
+
static int spi_master_initialize_queue(struct spi_master *master)
{
int ret;
dynamic = 1;
}
+ INIT_LIST_HEAD(&master->queue);
+ spin_lock_init(&master->queue_lock);
spin_lock_init(&master->bus_lock_spinlock);
mutex_init(&master->bus_lock_mutex);
master->bus_lock_flag = 0;
DECLARE_COMPLETION_ONSTACK(done);
int status;
struct spi_master *master = spi->master;
+ unsigned long flags;
+
+ status = __spi_validate(spi, message);
+ if (status != 0)
+ return status;
message->complete = spi_complete;
message->context = &done;
+ message->spi = spi;
if (!bus_locked)
mutex_lock(&master->bus_lock_mutex);
- status = spi_async_locked(spi, message);
+ /* If we're not using the legacy transfer method then we will
+ * try to transfer in the calling context so special case.
+ * This code would be less tricky if we could remove the
+ * support for driver implemented message queues.
+ */
+ if (master->transfer == spi_queued_transfer) {
+ spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+
+ trace_spi_message_submit(message);
+
+ status = __spi_queued_transfer(spi, message, false);
+
+ spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+ } else {
+ status = spi_async_locked(spi, message);
+ }
if (!bus_locked)
mutex_unlock(&master->bus_lock_mutex);
if (status == 0) {
+ /* Push out the messages in the calling context if we
+ * can.
+ */
+ if (master->transfer == spi_queued_transfer)
+ __spi_pump_messages(master, false);
+
wait_for_completion(&done);
status = message->status;
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff