Hi linux-media devs, this is similar to one of HCH's patches that
hasn't been applied yet.
The patch 7b4eeed174b7: "[media] vmalloc_sg: make sure all pages in
vmalloc area are really DMA-ready" from Jun 12, 2014, leads to the
following static checker warning:
drivers/media/v4l2-core/videobuf-dma-sg.c:236 videobuf_dma_init_kernel()
error: 'addr' came from dma_alloc_coherent() so we can't do virt_to_phys()
drivers/media/v4l2-core/videobuf-dma-sg.c
210 static int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
211 int nr_pages)
212 {
213 int i;
214
215 dprintk(1, "init kernel [%d pages]\n", nr_pages);
216
217 dma->direction = direction;
218 dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages),
219 GFP_KERNEL);
220 if (!dma->vaddr_pages)
221 return -ENOMEM;
222
223 dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL);
224 if (!dma->dma_addr) {
225 kfree(dma->vaddr_pages);
226 return -ENOMEM;
227 }
228 for (i = 0; i < nr_pages; i++) {
229 void *addr;
230
231 addr = dma_alloc_coherent(dma->dev, PAGE_SIZE,
^^^^^^^^^^^^^^^^^^^^^^^^^
232 &(dma->dma_addr[i]), GFP_KERNEL);
233 if (addr == NULL)
234 goto out_free_pages;
235
236 dma->vaddr_pages[i] = virt_to_page(addr);
^^^^^^^^^^^^^^^^^^
Apparently this isn't allowed.
237 }
238 dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP,
239 PAGE_KERNEL);
240 if (NULL == dma->vaddr) {
241 dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
242 goto out_free_pages;
243 }
244
245 dprintk(1, "vmalloc is at addr %p, size=%d\n",
246 dma->vaddr, nr_pages << PAGE_SHIFT);
247
248 memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT);
249 dma->nr_pages = nr_pages;
250
251 return 0;
252 out_free_pages:
253 while (i > 0) {
254 void *addr;
regards,
dan carpenter
