Re: [RFC,libdrm 1/3] tegra: Add stream library

I just skimmed the code of libdrm while I'm trying to understand the host1x driver. So below is what I found.

Mark On 12/13/2012 10:01 PM, Arto Meriläinen wrote:

From: Arto Merilainen amerilainen@nvidia.com

This patch introduces tegra stream library. The library is used for buffer management, command stream construction and work synchronization.

[...]

+/*

• • tegra_fence_is_valid(fence)
• • Check validity of a fence. We just check that the fence range
• • is valid w.r.t. host1x hardware.
• */

+int tegra_fence_is_valid(const struct tegra_fence *fence) +{

• int valid = fence ? 1 : 0;
• valid = valid && fence->id != (uint32_t) -1;
• valid = valid && fence->id < 32;

Hardcode here. Assume always has 32 syncpts. Change to a micro wrapped with tegra version ifdef will be better.

• return valid;

+}

[...]

• /* Add fences */
• if (num_fences) {

•    tegra_stream_push(stream,
  

•        nvhost_opcode_setclass(NV_HOST1X_CLASS_ID,
  

•        host1x_uclass_wait_syncpt_r(), num_fences));
  

•    for (; num_fences; num_fences--, fence++) {
  

•        assert(tegra_fence_is_valid(fence));
  

This is useless. We already add "1 + num_fences" to num_words above. So move this "assert" before adding "1 + num_fences" to num_words makes sense.

•        tegra_stream_push(stream, nvhost_class_host_wait_syncpt(fence->id,
  

•            fence->value));
  

•    }
  

• }
• if (class_id)

•    tegra_stream_push(stream, nvhost_opcode_setclass(class_id, 0, 0));
  

• return 0;

+}

[...]

+#endif /* TEGRA_DRMIF_H */