On Mon, Mar 21, 2016 at 01:26:58PM +0100, David Herrmann wrote: > Hi > > On Mon, Mar 21, 2016 at 8:51 AM, Daniel Vetter <daniel.vet...@ffwll.ch> wrote: > > Just a bit of wording polish plus mentioning that it can fail and must > > be restarted. > > > > Requested by Sumit. > > > > v2: Fix them typos (Hans). > > > > Cc: Chris Wilson <ch...@chris-wilson.co.uk> > > Cc: Tiago Vignatti <tiago.vigna...@intel.com> > > Cc: Stéphane Marchesin <marc...@chromium.org> > > Cc: David Herrmann <dh.herrm...@gmail.com> > > Cc: Sumit Semwal <sumit.sem...@linaro.org> > > Cc: Daniel Vetter <daniel.vet...@intel.com> > > CC: linux-me...@vger.kernel.org > > Cc: dri-de...@lists.freedesktop.org > > Cc: linaro-mm-...@lists.linaro.org > > Cc: intel-gfx@lists.freedesktop.org > > Cc: de...@driverdev.osuosl.org > > Cc: Hans Verkuil <hverk...@xs4all.nl> > > Acked-by: Sumit Semwal <sumit.sem...@linaro.org> > > Signed-off-by: Daniel Vetter <daniel.vet...@intel.com> > > --- > > Documentation/dma-buf-sharing.txt | 11 ++++++----- > > drivers/dma-buf/dma-buf.c | 2 +- > > 2 files changed, 7 insertions(+), 6 deletions(-) > > > > diff --git a/Documentation/dma-buf-sharing.txt > > b/Documentation/dma-buf-sharing.txt > > index 32ac32e773e1..ca44c5820585 100644 > > --- a/Documentation/dma-buf-sharing.txt > > +++ b/Documentation/dma-buf-sharing.txt > > @@ -352,7 +352,8 @@ Being able to mmap an export dma-buf buffer object has > > 2 main use-cases: > > > > No special interfaces, userspace simply calls mmap on the dma-buf fd, > > making > > sure that the cache synchronization ioctl (DMA_BUF_IOCTL_SYNC) is > > *always* > > - used when the access happens. This is discussed next paragraphs. > > + used when the access happens. Note that DMA_BUF_IOCTL_SYNC can fail with > > + -EAGAIN or -EINTR, in which case it must be restarted. > > What is "restart on EAGAIN" supposed to mean? Or more generally, what > does EAGAIN tell the caller?
Do what drmIoctl does essentially. while (ret == -1 && (errno == EAGAIN || errno == EINTR) ret = ioctl(); Typed from memery, too lazy to look it up in the source ;-) I'm trying to sell the idea of a real dma-buf manpage to Sumit, we should clarify this in detail there. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx