- if (!access_ok(VERIFY_READ, buf, count)) {
- IVTVFB_WARN("Invalid userspace pointer 0x%08lx\n",
- (unsigned long)buf);
- err = -EFAULT;
- }
-
- if (!err) {
- /* If transfer size > threshold and both src/dst
- addresses are aligned, use DMA */
- if (count >= 4096 &&
- ((unsigned long)buf & 3) == ((unsigned long)dst & 3)) {
- /* Odd address = can't DMA. Align */
- if ((unsigned long)dst & 3) {
- lead = 4 - ((unsigned long)dst & 3);
- memcpy(dst, buf, lead);
- buf += lead;
- dst += lead;
- }
- /* DMA resolution is 32 bits */
- if ((count - lead) & 3)
- tail = (count - lead) & 3;
- /* DMA the data */
- dma_size = count - lead - tail;
- err = ivtvfb_prep_dec_dma_to_device(itv,
- p + lead + dma_offset, (void *)buf, dma_size);
- dst += dma_size;
- buf += dma_size;
- /* Copy any leftover data */
- if (tail)
- memcpy(dst, buf, tail);
- } else {
- memcpy(dst, buf, count);
+ /* If transfer size > threshold and both src/dst
+ addresses are aligned, use DMA */
+ if (count >= 4096 &&
+ ((unsigned long)buf & 3) == ((unsigned long)dst & 3)) {
+ /* Odd address = can't DMA. Align */
+ if ((unsigned long)dst & 3) {
+ lead = 4 - ((unsigned long)dst & 3);
+ if (copy_from_user(dst, buf, lead))
+ return -EFAULT;
+ buf += lead;
+ dst += lead;