V4L/DVB (3195): Fix for 64-bit compile warning

- Add the fix for the saa7146 64-bit compile warning (again). This time with
comments and checked by Johannes Stezenbach.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/media/common/saa7146_hlp.c b/drivers/media/common/saa7146_hlp.c
index ec52dff8cb69..33bec8a6843b 100644
--- a/drivers/media/common/saa7146_hlp.c
+++ b/drivers/media/common/saa7146_hlp.c
@@ -562,19 +562,26 @@ static void saa7146_set_position(struct saa7146_dev *dev, int w_x, int w_y, int
 
         int b_depth = vv->ov_fmt->depth;
         int b_bpl = vv->ov_fb.fmt.bytesperline;
-        u32 base = (u32)vv->ov_fb.base;
+        /* The unsigned long cast is to remove a 64-bit compile warning since
+           it looks like a 64-bit address is cast to a 32-bit value, even
+           though the base pointer is really a 32-bit physical address that
+           goes into a 32-bit DMA register.
+           FIXME: might not work on some 64-bit platforms, but see the FIXME
+           in struct v4l2_framebuffer (videodev2.h) for that.
+         */
+        u32 base = (u32)(unsigned long)vv->ov_fb.base;
 
         struct  saa7146_video_dma vdma1;
 
         /* calculate memory offsets for picture, look if we shall top-down-flip */
         vdma1.pitch     = 2*b_bpl;
         if ( 0 == vv->vflip ) {
-                vdma1.base_even = (u32)base + (w_y * (vdma1.pitch/2)) + (w_x * (b_depth / 8));
+                vdma1.base_even = base + (w_y * (vdma1.pitch/2)) + (w_x * (b_depth / 8));
                 vdma1.base_odd  = vdma1.base_even + (vdma1.pitch / 2);
                 vdma1.prot_addr = vdma1.base_even + (w_height * (vdma1.pitch / 2));
         }
         else {
-                vdma1.base_even = (u32)base + ((w_y+w_height) * (vdma1.pitch/2)) + (w_x * (b_depth / 8));
+                vdma1.base_even = base + ((w_y+w_height) * (vdma1.pitch/2)) + (w_x * (b_depth / 8));
                 vdma1.base_odd  = vdma1.base_even - (vdma1.pitch / 2);
                 vdma1.prot_addr = vdma1.base_odd - (w_height * (vdma1.pitch / 2));
         }