[media] gspca_main: Set memory type to GSPCA_MEMORY_NO on buffer release

Before this patch we were not setting the memory type to GSPCA_MEMORY_NO
when the buffers were released by the app doing a reqbufs 0. Nor would
the memory type be set to GSPCA_MEMORY_NO on device close, as capture_file
already is NULL on device close because of the reqbufs 0. This caused the
following problem:
-app1 does reqbufs USERPTR for 4 buffers
-app1 does reqbufs USERPTR for 0 buffers
-app2 tries to do reqbufs MMAP for 4 buffers
 fails because gspca_dev->memory still is USERPTR

Fixing this also allows an app to switch memory type's by unrequesting
the buffers and re-requesting them of a different type.

This patch also moves the setting of gspca_dev->frsz and gscpa_dev->memory
to after alloc_frame succeeding, so that they are not changed when allocating
fails.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index 0ba42dd4b99b..adab34f91a68 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -508,8 +508,8 @@ static int gspca_is_compressed(__u32 format)
         return 0;
 }
 
-static int frame_alloc(struct gspca_dev *gspca_dev,
-                        unsigned int count)
+static int frame_alloc(struct gspca_dev *gspca_dev, struct file *file,
+                        enum v4l2_memory memory, unsigned int count)
 {
         struct gspca_frame *frame;
         unsigned int frsz;
@@ -519,7 +519,6 @@ static int frame_alloc(struct gspca_dev *gspca_dev,
         frsz = gspca_dev->cam.cam_mode[i].sizeimage;
         PDEBUG(D_STREAM, "frame alloc frsz: %d", frsz);
         frsz = PAGE_ALIGN(frsz);
-        gspca_dev->frsz = frsz;
         if (count >= GSPCA_MAX_FRAMES)
                 count = GSPCA_MAX_FRAMES - 1;
         gspca_dev->frbuf = vmalloc_32(frsz * count);
@@ -527,6 +526,9 @@ static int frame_alloc(struct gspca_dev *gspca_dev,
                 err("frame alloc failed");
                 return -ENOMEM;
         }
+        gspca_dev->capt_file = file;
+        gspca_dev->memory = memory;
+        gspca_dev->frsz = frsz;
         gspca_dev->nframes = count;
         for (i = 0; i < count; i++) {
                 frame = &gspca_dev->frame[i];
@@ -535,7 +537,7 @@ static int frame_alloc(struct gspca_dev *gspca_dev,
                 frame->v4l2_buf.flags = 0;
                 frame->v4l2_buf.field = V4L2_FIELD_NONE;
                 frame->v4l2_buf.length = frsz;
-                frame->v4l2_buf.memory = gspca_dev->memory;
+                frame->v4l2_buf.memory = memory;
                 frame->v4l2_buf.sequence = 0;
                 frame->data = gspca_dev->frbuf + i * frsz;
                 frame->v4l2_buf.m.offset = i * frsz;
@@ -558,6 +560,9 @@ static void frame_free(struct gspca_dev *gspca_dev)
                         gspca_dev->frame[i].data = NULL;
         }
         gspca_dev->nframes = 0;
+        gspca_dev->frsz = 0;
+        gspca_dev->capt_file = NULL;
+        gspca_dev->memory = GSPCA_MEMORY_NO;
 }
 
 static void destroy_urbs(struct gspca_dev *gspca_dev)
@@ -1250,8 +1255,6 @@ static int dev_close(struct file *file)
                         mutex_unlock(&gspca_dev->usb_lock);
                 }
                 frame_free(gspca_dev);
-                gspca_dev->capt_file = NULL;
-                gspca_dev->memory = GSPCA_MEMORY_NO;
         }
         file->private_data = NULL;
         module_put(gspca_dev->module);
@@ -1524,17 +1527,13 @@ static int vidioc_reqbufs(struct file *file, void *priv,
         }
 
         /* free the previous allocated buffers, if any */
-        if (gspca_dev->nframes != 0) {
+        if (gspca_dev->nframes != 0)
                 frame_free(gspca_dev);
-                gspca_dev->capt_file = NULL;
-        }
         if (rb->count == 0)                     /* unrequest */
                 goto out;
-        gspca_dev->memory = rb->memory;
-        ret = frame_alloc(gspca_dev, rb->count);
+        ret = frame_alloc(gspca_dev, file, rb->memory, rb->count);
         if (ret == 0) {
                 rb->count = gspca_dev->nframes;
-                gspca_dev->capt_file = file;
                 if (streaming)
                         ret = gspca_init_transfer(gspca_dev);
         }