Hi, On Tuesday 27 July 2010 14:21:40 Figo.zhang wrote: > a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping > when it encounter page fault at video_vm_ops->fault(). > > a new implementation for mmap, it translate the vmalloc to page at > video_vm_ops->fault().
How is that supposed to work ? mem->dma.vmalloc is NULL in the vm_fault handler for V4L2_MEMORY_MMAP buffers. Have you tested the code at all ? > Signed-off-by: Figo.zhang <[email protected]> > --- > drivers/media/video/videobuf-dma-sg.c | 38 > ++++++++++++++++++++++++++++---- > 1 files changed, 33 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/video/videobuf-dma-sg.c > b/drivers/media/video/videobuf-dma-sg.c > index 8359e6b..c9a8817 100644 > --- a/drivers/media/video/videobuf-dma-sg.c > +++ b/drivers/media/video/videobuf-dma-sg.c > @@ -397,16 +397,44 @@ static void videobuf_vm_close(struct > vm_area_struct *vma) > */ > static int videobuf_vm_fault(struct vm_area_struct *vma, struct > vm_fault *vmf) > { > - struct page *page; > + struct page *page = NULL; > + struct videobuf_mapping *map = vma->vm_private_data; > + struct videobuf_queue *q = map->q; > + struct videobuf_dma_sg_memory *mem = NULL; > + > + unsigned long offset; > + unsigned long page_nr; > + int first; > > dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n", > (unsigned long)vmf->virtual_address, > vma->vm_start, vma->vm_end); > > - page = alloc_page(GFP_USER | __GFP_DMA32); > - if (!page) > - return VM_FAULT_OOM; > - clear_user_highpage(page, (unsigned long)vmf->virtual_address); > + mutex_lock(&q->vb_lock); > + > + offset = (unsigned long)vmf->virtual_address - vma->vm_start; > + page_nr = offset >> PAGE_SHIFT; > + > + for (first = 0; first < VIDEO_MAX_FRAME; first++) { > + if (NULL == q->bufs[first]) > + continue; > + > + MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); > + > + if (q->bufs[first]->map == map) > + break; > + } > + > + mem = q->bufs[first]->priv; > + if (!mem) > + return VM_FAULT_SIGBUS; > + if (mem->dma.vmalloc) > + page = vmalloc_to_page(mem->dma.vmalloc+ > + (offset & (~PAGE_MASK))); > + if (mem->dma.pages) > + page = mem->dma.pages[page_nr]; > + mutex_unlock(&q->vb_lock); > + > vmf->page = page; > > return 0; -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
