Hi Andreas,
On Wed, Apr 11, 2018 at 06:59:03AM +0200, Andreas Kemnade wrote:
> Hi Ladis,
>
> On Tue, 10 Apr 2018 22:56:43 +0200
> Ladislav Michl <ladis@xxxxxxxxxxxxxx> wrote:
>
> > Hi Nikolaus,
> >
> > On Tue, Apr 10, 2018 at 06:25:17PM +0200, H. Nikolaus Schaller wrote:
> > > Hi,
> > > we just started testing the v4.16 kernel and found the
> > > device no longer bootable (works with v4.15). It turned
> > > out that there was a harmful modification somewhere between
> > > v4.15.0 and v4.16-rc1.
> > >
> > > A git bisect points to this patch:
> >
> > Well, that's a shame... However, this code is in production for several
> > months now, so could you, please put 'goto out_copy' if 'buf >= high_memory'
> > condition is met, ie:
> > --- a/drivers/mtd/nand/onenand/omap2.c
> > +++ b/drivers/mtd/nand/onenand/omap2.c
> > @@ -392,6 +392,7 @@ static int omap2_onenand_read_bufferram(struct mtd_info *mtd, int area,
> > if (buf >= high_memory) {
> > struct page *p1;
> >
> > + goto out_copy;
> > if (((size_t)buf & PAGE_MASK) !=
> > ((size_t)(buf + count - 1) & PAGE_MASK))
> > goto out_copy;
>
> I had the same problem here, and that snippet helps here. ubiattach
> -p /dev/mtdX does not cause kernel oopses here anymore
It seems reviving old code always comes at a price :-) Could you try
following patch, so far compile tested only?
(we'll need to do the same for omap2_onenand_write_bufferram, but
it sould be enough for testing purposes now)
diff --git a/drivers/mtd/nand/onenand/omap2.c b/drivers/mtd/nand/onenand/omap2.c
index 9c159f0dd9a6..04cefd7a6487 100644
--- a/drivers/mtd/nand/onenand/omap2.c
+++ b/drivers/mtd/nand/onenand/omap2.c
@@ -375,11 +375,12 @@ static int omap2_onenand_read_bufferram(struct mtd_info *mtd, int area,
{
struct omap2_onenand *c = container_of(mtd, struct omap2_onenand, mtd);
struct onenand_chip *this = mtd->priv;
+ struct device *dev = &c->pdev->dev;
dma_addr_t dma_src, dma_dst;
int bram_offset;
void *buf = (void *)buffer;
size_t xtra;
- int ret;
+ int ret, page_dma = 0;
bram_offset = omap2_onenand_bufferram_offset(mtd, area) + area + offset;
if (bram_offset & 3 || (size_t)buf & 3 || count < 384)
@@ -389,38 +390,43 @@ static int omap2_onenand_read_bufferram(struct mtd_info *mtd, int area,
if (in_interrupt() || oops_in_progress)
goto out_copy;
+ xtra = count & 3;
+ if (xtra) {
+ count -= xtra;
+ memcpy(buf + count, this->base + bram_offset + count, xtra);
+ }
+
+ /* Handle vmalloc address */
if (buf >= high_memory) {
- struct page *p1;
+ struct page *page;
if (((size_t)buf & PAGE_MASK) !=
((size_t)(buf + count - 1) & PAGE_MASK))
goto out_copy;
- p1 = vmalloc_to_page(buf);
- if (!p1)
+ page = vmalloc_to_page(buf);
+ if (!page)
goto out_copy;
- buf = page_address(p1) + ((size_t)buf & ~PAGE_MASK);
- }
-
- xtra = count & 3;
- if (xtra) {
- count -= xtra;
- memcpy(buf + count, this->base + bram_offset + count, xtra);
+ page_dma = 1;
+ dma_dst = dma_map_page(dev, page, (size_t) buf & ~PAGE_MASK,
+ count, DMA_FROM_DEVICE);
+ } else {
+ dma_dst = dma_map_single(dev, buf, count, DMA_FROM_DEVICE);
}
-
dma_src = c->phys_base + bram_offset;
- dma_dst = dma_map_single(&c->pdev->dev, buf, count, DMA_FROM_DEVICE);
- if (dma_mapping_error(&c->pdev->dev, dma_dst)) {
- dev_err(&c->pdev->dev,
- "Couldn't DMA map a %d byte buffer\n",
- count);
+
+ if (dma_mapping_error(dev, dma_dst)) {
+ dev_err(dev, "Couldn't DMA map a %d byte buffer\n", count);
goto out_copy;
}
ret = omap2_onenand_dma_transfer(c, dma_src, dma_dst, count);
- dma_unmap_single(&c->pdev->dev, dma_dst, count, DMA_FROM_DEVICE);
+ if (page_dma)
+ dma_unmap_page(dev, dma_dst, count, DMA_FROM_DEVICE);
+ else
+ dma_unmap_single(dev, dma_dst, count, DMA_FROM_DEVICE);
if (ret) {
- dev_err(&c->pdev->dev, "timeout waiting for DMA\n");
+ dev_err(dev, "timeout waiting for DMA\n");
goto out_copy;
}
--
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