On Fri, 14 Dec 2012 09:06:03 +0200 Andy Shevchenko <[email protected]> wrote:
> On Fri, Dec 14, 2012 at 1:34 AM, Andrew Morton > <[email protected]> wrote: > > On Mon, 10 Dec 2012 13:37:44 +0200 > > Andy Shevchenko <[email protected]> wrote: > > > >> We get a warning if CONFIG_DMA_API_DEBUG=y > >> > >> [ 28.150631] WARNING: at lib/dma-debug.c:933 check_unmap+0x5d6/0x6ac() > >> [ 28.157058] dw_dmac dw_dmac.0: DMA-API: device driver failed to check > >> map error[device address=0x0000000035698305] [size=14365 bytes] [mapped as > >> single] > > >> --- a/drivers/dma/dmatest.c > >> +++ b/drivers/dma/dmatest.c > >> @@ -378,15 +378,35 @@ static int dmatest_func(void *data) > >> > >> dma_srcs[i] = dma_map_single(dev->dev, buf, len, > >> DMA_TO_DEVICE); > >> + ret = dma_mapping_error(dev->dev, dma_srcs[i]); > >> + if (ret) { > >> + unmap_src(dev->dev, dma_srcs, len, i); > >> + pr_warn("%s: #%u: mapping error %d with " > >> + "src_off=0x%x len=0x%x\n", > >> + thread_name, total_tests - 1, ret, > >> + src_off, len); > >> + failed_tests++; > >> + continue; > >> + } > > > > The changelog and the code don't match. Which one is out of date? > > I'm afraid I didn't get what is wrong. > The above code will not emit the string "dw_dmac dw_dmac.0: DMA-API: device driver failed to check map error[device address=0x0000000035698305] [size=14365 bytes] [mapped as single]". Oh I see what you did. That string is emitted by the kernel at present, and the patch prevents this. And it also emits a new warning if the mapping attempt failed, and that new warning wasn't described. I updated the changelog: : The kernel emits a warning if CONFIG_DMA_API_DEBUG=y: : : [ 28.150631] WARNING: at lib/dma-debug.c:933 check_unmap+0x5d6/0x6ac() : [ 28.157058] dw_dmac dw_dmac.0: DMA-API: device driver failed to check map error[device address=0x0000000035698305] [size=14365 bytes] [mapped as single] : : Fix this by adding the required checking of the dma_map_single() return : value. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
