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V4L/DVB (11819): Siano: smscore - fix get_common_buffer bug

get common buffers() should block operation until valid buffer
is avaliable.

Signed-off-by: Uri Shkolnik <uris@siano-ms.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Uri Shkolnik 2009-05-17 05:59:37 -03:00 committed by Mauro Carvalho Chehab
parent 9504ccacd7
commit a9349315f6

View File

@ -30,6 +30,7 @@
#include <linux/io.h>
#include <linux/firmware.h>
#include <linux/wait.h>
#include "smscoreapi.h"
#include "sms-cards.h"
@ -352,6 +353,9 @@ int smscore_register_device(struct smsdevice_params_t *params,
init_completion(&dev->resume_done);
init_completion(&dev->ir_init_done);
/* Buffer management */
init_waitqueue_head(&dev->buffer_mng_waitq);
/* alloc common buffer */
dev->common_buffer_size = params->buffer_size * params->num_buffers;
dev->common_buffer = dma_alloc_coherent(NULL, dev->common_buffer_size,
@ -686,7 +690,9 @@ void smscore_unregister_device(struct smscore_device_t *coredev)
* onresponse must no longer be called */
while (1) {
while ((cb = smscore_getbuffer(coredev))) {
while (!list_empty(&coredev->buffers)) {
cb = (struct smscore_buffer_t *) coredev->buffers.next;
list_del(&cb->entry);
kfree(cb);
num_buffers++;
}
@ -707,8 +713,10 @@ void smscore_unregister_device(struct smscore_device_t *coredev)
if (coredev->common_buffer)
dma_free_coherent(NULL, coredev->common_buffer_size,
coredev->common_buffer,
coredev->common_buffer_phys);
coredev->common_buffer, coredev->common_buffer_phys);
if (coredev->fw_buf != NULL)
kfree(coredev->fw_buf);
list_del(&coredev->entry);
kfree(coredev);
@ -1071,12 +1079,24 @@ struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev)
struct smscore_buffer_t *cb = NULL;
unsigned long flags;
DEFINE_WAIT(wait);
spin_lock_irqsave(&coredev->bufferslock, flags);
if (!list_empty(&coredev->buffers)) {
cb = (struct smscore_buffer_t *) coredev->buffers.next;
list_del(&cb->entry);
}
/* This function must return a valid buffer, since the buffer list is
* finite, we check that there is an available buffer, if not, we wait
* until such buffer become available.
*/
prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE);
if (list_empty(&coredev->buffers))
schedule();
finish_wait(&coredev->buffer_mng_waitq, &wait);
cb = (struct smscore_buffer_t *) coredev->buffers.next;
list_del(&cb->entry);
spin_unlock_irqrestore(&coredev->bufferslock, flags);
@ -1093,8 +1113,8 @@ EXPORT_SYMBOL_GPL(smscore_getbuffer);
*
*/
void smscore_putbuffer(struct smscore_device_t *coredev,
struct smscore_buffer_t *cb)
{
struct smscore_buffer_t *cb) {
wake_up_interruptible(&coredev->buffer_mng_waitq);
list_add_locked(&cb->entry, &coredev->buffers, &coredev->bufferslock);
}
EXPORT_SYMBOL_GPL(smscore_putbuffer);