On systems where it cannot be assured that enough continous memory is available
all the time it can be very useful to only allocate the memory once when it is
needed the first time. Afterwards the initially allocated memory will be
reused, so it is ensured that the memory will stay available until the driver
is unloaded.
Signed-off-by: Julian Scheel <julian@xxxxxxxx>
---
drivers/media/video/tm6000/tm6000-video.c | 111 +++++++++++++++++++++++++-----
drivers/media/video/tm6000/tm6000.h | 5 ++
2 files changed, 97 insertions(+), 19 deletions(-)
diff --git a/drivers/media/video/tm6000/tm6000-video.c b/drivers/media/video/tm6000/tm6000-video.c
index 03de3d8..1b8db35 100644
--- a/drivers/media/video/tm6000/tm6000-video.c
+++ b/drivers/media/video/tm6000/tm6000-video.c
@@ -49,12 +49,15 @@
#define TM6000_MIN_BUF 4
#define TM6000_DEF_BUF 8
+#define TM6000_NUM_URB_BUF 8
+
#define TM6000_MAX_ISO_PACKETS 46 /* Max number of ISO packets */
/* Declare static vars that will be used as parameters */
static unsigned int vid_limit = 16; /* Video memory limit, in Mb */
static int video_nr = -1; /* /dev/videoN, -1 for autodetect */
static int radio_nr = -1; /* /dev/radioN, -1 for autodetect */
+static int keep_urb = 0; /* keep urb buffers allocated */
/* Debug level */
int tm6000_debug;
@@ -570,6 +573,70 @@ static void tm6000_irq_callback(struct urb *urb)
}
/*
+ * Allocate URB buffers
+ */
+static int tm6000_alloc_urb_buffers(struct tm6000_core *dev)
+{
+ int num_bufs = TM6000_NUM_URB_BUF;
+ int i;
+
+ if (dev->urb_buffer != NULL)
+ return 0;
+
+ dev->urb_buffer = kmalloc(sizeof(void *)*num_bufs, GFP_KERNEL);
+ if (!dev->urb_buffer) {
+ tm6000_err("cannot allocate memory for urb buffers\n");
+ return -ENOMEM;
+ }
+
+ dev->urb_dma = kmalloc(sizeof(dma_addr_t *)*num_bufs, GFP_KERNEL);
+ if (!dev->urb_dma) {
+ tm6000_err("cannot allocate memory for urb dma pointers\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < num_bufs; i++) {
+ dev->urb_buffer[i] = usb_alloc_coherent(dev->udev, dev->urb_size,
+ GFP_KERNEL, &dev->urb_dma[i]);
+ if (!dev->urb_buffer[i]) {
+ tm6000_err("unable to allocate %i bytes for transfer"
+ " buffer %i\n", dev->urb_size, i);
+ return -ENOMEM;
+ }
+ memset(dev->urb_buffer[i], 0, dev->urb_size);
+ }
+
+ return 0;
+}
+
+/*
+ * Free URB buffers
+ */
+static int tm6000_free_urb_buffers(struct tm6000_core *dev)
+{
+ int i;
+
+ if (dev->urb_buffer == NULL)
+ return 0;
+
+ for (i = 0; i < TM6000_NUM_URB_BUF; i++) {
+ if (dev->urb_buffer[i]) {
+ usb_free_coherent(dev->udev,
+ dev->urb_size,
+ dev->urb_buffer[i],
+ dev->urb_dma[i]);
+ dev->urb_buffer[i] = NULL;
+ }
+ }
+ kfree (dev->urb_buffer);
+ kfree (dev->urb_dma);
+ dev->urb_buffer = NULL;
+ dev->urb_dma = NULL;
+
+ return 0;
+}
+
+/*
* Stop and Deallocate URBs
*/
static void tm6000_uninit_isoc(struct tm6000_core *dev)
@@ -585,18 +652,15 @@ static void tm6000_uninit_isoc(struct tm6000_core *dev)
if (urb) {
usb_kill_urb(urb);
usb_unlink_urb(urb);
- if (dev->isoc_ctl.transfer_buffer[i]) {
- usb_free_coherent(dev->udev,
- urb->transfer_buffer_length,
- dev->isoc_ctl.transfer_buffer[i],
- urb->transfer_dma);
- }
usb_free_urb(urb);
dev->isoc_ctl.urb[i] = NULL;
}
dev->isoc_ctl.transfer_buffer[i] = NULL;
}
+ if (!keep_urb)
+ tm6000_free_urb_buffers(dev);
+
kfree(dev->isoc_ctl.urb);
kfree(dev->isoc_ctl.transfer_buffer);
@@ -606,12 +670,12 @@ static void tm6000_uninit_isoc(struct tm6000_core *dev)
}
/*
- * Allocate URBs and start IRQ
+ * Assign URBs and start IRQ
*/
static int tm6000_prepare_isoc(struct tm6000_core *dev)
{
struct tm6000_dmaqueue *dma_q = &dev->vidq;
- int i, j, sb_size, pipe, size, max_packets, num_bufs = 8;
+ int i, j, sb_size, pipe, size, max_packets, num_bufs = TM6000_NUM_URB_BUF;
struct urb *urb;
/* De-allocates all pending stuff */
@@ -634,6 +698,7 @@ static int tm6000_prepare_isoc(struct tm6000_core *dev)
max_packets = TM6000_MAX_ISO_PACKETS;
sb_size = max_packets * size;
+ dev->urb_size = sb_size;
dev->isoc_ctl.num_bufs = num_bufs;
@@ -656,6 +721,17 @@ static int tm6000_prepare_isoc(struct tm6000_core *dev)
max_packets, num_bufs, sb_size,
dev->isoc_in.maxsize, size);
+
+ if (!dev->urb_buffer && tm6000_alloc_urb_buffers(dev) < 0) {
+ tm6000_err("cannot allocate memory for urb buffers\n");
+
+ /* call free, as some buffers might have been allocated */
+ tm6000_free_urb_buffers(dev);
+ kfree(dev->isoc_ctl.urb);
+ kfree(dev->isoc_ctl.transfer_buffer);
+ return -ENOMEM;
+ }
+
/* allocate urbs and transfer buffers */
for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
urb = usb_alloc_urb(max_packets, GFP_KERNEL);
@@ -667,17 +743,8 @@ static int tm6000_prepare_isoc(struct tm6000_core *dev)
}
dev->isoc_ctl.urb[i] = urb;
- dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(dev->udev,
- sb_size, GFP_KERNEL, &urb->transfer_dma);
- if (!dev->isoc_ctl.transfer_buffer[i]) {
- tm6000_err("unable to allocate %i bytes for transfer"
- " buffer %i%s\n",
- sb_size, i,
- in_interrupt() ? " while in int" : "");
- tm6000_uninit_isoc(dev);
- return -ENOMEM;
- }
- memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
+ urb->transfer_dma = dev->urb_dma[i];
+ dev->isoc_ctl.transfer_buffer[i] = dev->urb_buffer[i];
usb_fill_bulk_urb(urb, dev->udev, pipe,
dev->isoc_ctl.transfer_buffer[i], sb_size,
@@ -1833,6 +1900,9 @@ int tm6000_v4l2_unregister(struct tm6000_core *dev)
{
video_unregister_device(dev->vfd);
+ /* if URB buffers are still allocated free them now */
+ tm6000_free_urb_buffers(dev);
+
if (dev->radio_dev) {
if (video_is_registered(dev->radio_dev))
video_unregister_device(dev->radio_dev);
@@ -1858,3 +1928,6 @@ MODULE_PARM_DESC(debug, "activates debug info");
module_param(vid_limit, int, 0644);
MODULE_PARM_DESC(vid_limit, "capture memory limit in megabytes");
+module_param(keep_urb, bool, 0);
+MODULE_PARM_DESC(keep_urb, "Keep urb buffers allocated even when the device "
+ "is closed by the user");
diff --git a/drivers/media/video/tm6000/tm6000.h b/drivers/media/video/tm6000/tm6000.h
index 6531d16..4bd3a0d 100644
--- a/drivers/media/video/tm6000/tm6000.h
+++ b/drivers/media/video/tm6000/tm6000.h
@@ -267,6 +267,11 @@ struct tm6000_core {
spinlock_t slock;
+ /* urb dma buffers */
+ char **urb_buffer;
+ dma_addr_t *urb_dma;
+ unsigned int urb_size;
+
unsigned long quirks;
};
--
1.7.12.2
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