From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
If the saa7134 module is loaded with the saa7134_userptr set to 1,
then USERPTR support is enabled. A check in buffer_prepare
verifies that the pointer is page-aligned.
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
drivers/media/pci/saa7134/saa7134-core.c | 4 ++++
drivers/media/pci/saa7134/saa7134-vbi.c | 4 ++++
drivers/media/pci/saa7134/saa7134-video.c | 16 +++++++++++++---
drivers/media/pci/saa7134/saa7134.h | 1 +
4 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
index f4ea0ec..be19a05 100644
--- a/drivers/media/pci/saa7134/saa7134-core.c
+++ b/drivers/media/pci/saa7134/saa7134-core.c
@@ -69,6 +69,10 @@ module_param_named(no_overlay, saa7134_no_overlay, int, 0444);
MODULE_PARM_DESC(no_overlay,"allow override overlay default (0 disables, 1 enables)"
" [some VIA/SIS chipsets are known to have problem with overlay]");
+bool saa7134_userptr;
+module_param(saa7134_userptr, bool, 0644);
+MODULE_PARM_DESC(saa7134_userptr, "enable page-aligned userptr support");
+
static unsigned int video_nr[] = {[0 ... (SAA7134_MAXBOARDS - 1)] = UNSET };
static unsigned int vbi_nr[] = {[0 ... (SAA7134_MAXBOARDS - 1)] = UNSET };
static unsigned int radio_nr[] = {[0 ... (SAA7134_MAXBOARDS - 1)] = UNSET };
diff --git a/drivers/media/pci/saa7134/saa7134-vbi.c b/drivers/media/pci/saa7134/saa7134-vbi.c
index 4479af5..c06dbe1 100644
--- a/drivers/media/pci/saa7134/saa7134-vbi.c
+++ b/drivers/media/pci/saa7134/saa7134-vbi.c
@@ -122,6 +122,10 @@ static int buffer_prepare(struct vb2_buffer *vb2)
unsigned int size;
int ret;
+ if (dma->sgl->offset) {
+ pr_err("The buffer is not page-aligned\n");
+ return -EINVAL;
+ }
size = dev->vbi_hlen * dev->vbi_vlen * 2;
if (vb2_plane_size(vb2, 0) < size)
return -EINVAL;
diff --git a/drivers/media/pci/saa7134/saa7134-video.c b/drivers/media/pci/saa7134/saa7134-video.c
index e50c950..828910c 100644
--- a/drivers/media/pci/saa7134/saa7134-video.c
+++ b/drivers/media/pci/saa7134/saa7134-video.c
@@ -878,6 +878,10 @@ static int buffer_prepare(struct vb2_buffer *vb2)
unsigned int size;
int ret;
+ if (dma->sgl->offset) {
+ pr_err("The buffer is not page-aligned\n");
+ return -EINVAL;
+ }
size = (dev->width * dev->height * dev->fmt->depth) >> 3;
if (vb2_plane_size(vb2, 0) < size)
return -EINVAL;
@@ -2055,11 +2059,15 @@ int saa7134_video_init1(struct saa7134_dev *dev)
q = &dev->video_vbq;
q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
/*
- * Do not add VB2_USERPTR: the saa7134 DMA engine cannot handle
- * transfers that do not start at the beginning of a page. A USERPTR
- * can start anywhere in a page, so USERPTR support is a no-go.
+ * Do not add VB2_USERPTR unless explicitly requested: the saa7134 DMA
+ * engine cannot handle transfers that do not start at the beginning
+ * of a page. A user-provided pointer can start anywhere in a page, so
+ * USERPTR support is a no-go unless the application knows about these
+ * limitations and has special support for this.
*/
q->io_modes = VB2_MMAP | VB2_READ;
+ if (saa7134_userptr)
+ q->io_modes |= VB2_USERPTR;
q->drv_priv = &dev->video_q;
q->ops = &vb2_qops;
q->gfp_flags = GFP_DMA32;
@@ -2076,6 +2084,8 @@ int saa7134_video_init1(struct saa7134_dev *dev)
q->type = V4L2_BUF_TYPE_VBI_CAPTURE;
/* Don't add VB2_USERPTR, see comment above */
q->io_modes = VB2_MMAP | VB2_READ;
+ if (saa7134_userptr)
+ q->io_modes |= VB2_USERPTR;
q->drv_priv = &dev->vbi_q;
q->ops = &saa7134_vbi_qops;
q->gfp_flags = GFP_DMA32;
diff --git a/drivers/media/pci/saa7134/saa7134.h b/drivers/media/pci/saa7134/saa7134.h
index f3032a1..c258495 100644
--- a/drivers/media/pci/saa7134/saa7134.h
+++ b/drivers/media/pci/saa7134/saa7134.h
@@ -714,6 +714,7 @@ static inline bool is_empress(struct file *file)
extern struct list_head saa7134_devlist;
extern struct mutex saa7134_devlist_lock;
extern int saa7134_no_overlay;
+extern bool saa7134_userptr;
void saa7134_track_gpio(struct saa7134_dev *dev, char *msg);
void saa7134_set_gpio(struct saa7134_dev *dev, int bit_no, int value);
--
1.9.2
--
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