On 25/06/2019 12:47, Dan Carpenter wrote:
On Tue, Jun 25, 2019 at 12:26:59PM +0100, Ian Abbott wrote:
drivers/staging/comedi/comedi_buf.c | 150 ++++++++++++++++++---------
drivers/staging/comedi/comedi_fops.c | 39 ++++---
2 files changed, 125 insertions(+), 64 deletions(-)
diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index d2c8cc72a99d..3ef3ddabf139 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -27,18 +27,19 @@ static void comedi_buf_map_kref_release(struct kref *kref)
unsigned int i;
if (bm->page_list) {
- for (i = 0; i < bm->n_pages; i++) {
- buf = &bm->page_list[i];
- clear_bit(PG_reserved,
- &(virt_to_page(buf->virt_addr)->flags));
- if (bm->dma_dir != DMA_NONE) {
-#ifdef CONFIG_HAS_DMA
- dma_free_coherent(bm->dma_hw_dev,
- PAGE_SIZE,
- buf->virt_addr,
- buf->dma_addr);
-#endif
- } else {
+ if (bm->dma_dir != DMA_NONE) {
+ /*
+ * DMA buffer was allocated as a single block.
+ * Address is in page_list[0].
+ */
+ buf = &bm->page_list[0];
+ dma_free_coherent(bm->dma_hw_dev,
+ PAGE_SIZE * bm->n_pages,
+ buf->virt_addr, buf->dma_addr);
+ } else {
+ for (i = 0; i < bm->n_pages; i++) {
+ buf = &bm->page_list[i];
+ ClearPageReserved(virt_to_page(buf->virt_addr));
I think we need a NULL check here:
if (!buf->virt_addr)
continue;
free_page((unsigned long)buf->virt_addr);
}
}
Hi Dan, I don't think that is strictly required because bm->n_pages gets
set to the number of successfully allocated pages (not the number of
required pages) by comedi_buf_map_alloc():
> + for (i = 0; i < n_pages; i++) {
> + buf = &bm->page_list[i];
> + buf->virt_addr = (void *)get_zeroed_page(GFP_KERNEL);
> + if (!buf->virt_addr)
> + break;
> +
> + SetPageReserved(virt_to_page(buf->virt_addr));
> + }
> +
> + bm->n_pages = i;
Here! ^
> + if (i < n_pages)
> + goto err;
> +err:
> + comedi_buf_map_put(bm);
> + return NULL;
--
-=( Ian Abbott <abbotti@xxxxxxxxx> || Web: www.mev.co.uk )=-
-=( MEV Ltd. is a company registered in England & Wales. )=-
-=( Registered number: 02862268. Registered address: )=-
-=( 15 West Park Road, Bramhall, STOCKPORT, SK7 3JZ, UK. )=-
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
