Re: [PATCH 2/3] drm/tegra: Deliver syncpoint base to user space

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 10/11/2013 12:43 PM, Thierry Reding wrote:
* PGP Signed by an unknown key

On Wed, Oct 09, 2013 at 02:54:09PM +0300, Arto Merilainen wrote:
This patch makes the necessary additions to deliver syncpoint base
to the user space.

This patch splits the index field in the drm_tegra_get_syncpt structure
into three separate fields (index, support_base, base_id). This allows
to keep compatibility over kernel versions:
- The placing of index field stays constant and therefore the interface
   should stay compatible with earlier userspace versions.
- The old index field was input-only and it was not supposed to be read
   afterwards. Delivering data back in the same field should not introduce
   regressions to any old user space applications.
- Old kernels left support_base and base_id fields intact (zero) and
   hence the new user space applications get the correct response from
   the kernel (=syncpoint does not have a base).

Signed-off-by: Arto Merilainen <amerilainen@xxxxxxxxxx>
---
  drivers/gpu/host1x/drm/drm.c | 2 ++
  include/uapi/drm/tegra_drm.h | 4 +++-
  2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/host1x/drm/drm.c b/drivers/gpu/host1x/drm/drm.c
index 8c61cee..4251563 100644
--- a/drivers/gpu/host1x/drm/drm.c
+++ b/drivers/gpu/host1x/drm/drm.c
@@ -468,6 +468,8 @@ static int tegra_get_syncpt(struct drm_device *drm, void *data,

  	syncpt = context->client->syncpts[args->index];
  	args->id = host1x_syncpt_id(syncpt);
+	args->support_base = syncpt->base ? 1 : 0;
+	args->base_id = syncpt->base ? syncpt->base->id : 0;

  	return 0;
  }
diff --git a/include/uapi/drm/tegra_drm.h b/include/uapi/drm/tegra_drm.h
index 73bde4e..7a79ca5 100644
--- a/include/uapi/drm/tegra_drm.h
+++ b/include/uapi/drm/tegra_drm.h
@@ -61,7 +61,9 @@ struct drm_tegra_close_channel {

  struct drm_tegra_get_syncpt {
  	__u64 context;
-	__u32 index;
+	__u16 index;
+	__u8 support_base;
+	__u8 base_id;
  	__u32 id;

I don't like this. Can't we just add a separate IOCTL? Something like:

Sure. This felt like a good idea, but I must admit I had a bit mixed feelings after looking my own explanation why this would be ok...

- Arto

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux