drivers/gpu/drm/amd/display/dc/link/link_resource.c
Source file repositories/reference/linux-study-clean/drivers/gpu/drm/amd/display/dc/link/link_resource.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/gpu/drm/amd/display/dc/link/link_resource.c- Extension
.c- Size
- 3920 bytes
- Lines
- 115
- Domain
- Driver Families
- Bucket
- drivers/gpu
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
link_resource.hprotocols/link_dp_capability.h
Detected Declarations
function filesfunction link_get_cur_res_mapfunction link_restore_res_map
Annotated Snippet
if (pipe->stream && pipe->stream->link && pipe->top_pipe == NULL) {
if (pipe->stream->link == link) {
*link_res = pipe->link_res;
break;
}
}
}
}
void link_get_cur_res_map(const struct dc *dc, uint32_t *map)
{
struct dc_link *link;
uint32_t i;
uint32_t hpo_dp_recycle_map = 0;
*map = 0;
if (dc->caps.dp_hpo) {
for (i = 0; i < dc->caps.max_links; i++) {
link = dc->links[i];
if (link->link_status.link_active &&
link_dp_get_encoding_format(&link->reported_link_cap) == DP_128b_132b_ENCODING &&
link_dp_get_encoding_format(&link->cur_link_settings) != DP_128b_132b_ENCODING)
/* hpo dp link encoder is considered as recycled, when RX reports 128b/132b encoding capability
* but current link doesn't use it.
*/
hpo_dp_recycle_map |= (1 << i);
}
*map |= (hpo_dp_recycle_map << LINK_RES_HPO_DP_REC_MAP__SHIFT);
}
}
void link_restore_res_map(const struct dc *dc, uint32_t *map)
{
struct dc_link *link;
uint32_t i;
unsigned int available_hpo_dp_count;
uint32_t hpo_dp_recycle_map = (*map & LINK_RES_HPO_DP_REC_MAP__MASK)
>> LINK_RES_HPO_DP_REC_MAP__SHIFT;
if (dc->caps.dp_hpo) {
available_hpo_dp_count = dc->res_pool->hpo_dp_link_enc_count;
/* remove excess 128b/132b encoding support for not recycled links */
for (i = 0; i < dc->caps.max_links; i++) {
if ((hpo_dp_recycle_map & (1 << i)) == 0) {
link = dc->links[i];
if (link->type != dc_connection_none &&
link_dp_get_encoding_format(&link->verified_link_cap) == DP_128b_132b_ENCODING) {
if (available_hpo_dp_count > 0)
available_hpo_dp_count--;
else
/* remove 128b/132b encoding capability by limiting verified link rate to HBR3 */
link->verified_link_cap.link_rate = LINK_RATE_HIGH3;
}
}
}
/* remove excess 128b/132b encoding support for recycled links */
for (i = 0; i < dc->caps.max_links; i++) {
if ((hpo_dp_recycle_map & (1 << i)) != 0) {
link = dc->links[i];
if (link->type != dc_connection_none &&
link_dp_get_encoding_format(&link->verified_link_cap) == DP_128b_132b_ENCODING) {
if (available_hpo_dp_count > 0)
available_hpo_dp_count--;
else
/* remove 128b/132b encoding capability by limiting verified link rate to HBR3 */
link->verified_link_cap.link_rate = LINK_RATE_HIGH3;
}
}
}
}
}
Annotation
- Immediate include surface: `link_resource.h`, `protocols/link_dp_capability.h`.
- Detected declarations: `function files`, `function link_get_cur_res_map`, `function link_restore_res_map`.
- Atlas domain: Driver Families / drivers/gpu.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.