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@nvidia.com
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:
struct drm_tegra_get_syncpt_base { __u64 context; __u32 syncpt; __u32 base; };
Which could be used somewhat like this:
struct drm_tegra_get_syncpt_base args;
memset(&args, 0, sizeof(args)); args.context = context; args.syncpt = syncpt;
err = ioctl(fd, DRM_IOCTL_TEGRA_GET_SYNCPT_BASE, &args); if (err < 0) { /* * perhaps errno == ENOTSUP if the syncpoint has no * associated base? */ }
base = args.base;
Thierry