diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
-rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 65 |
1 files changed, 37 insertions, 28 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 4b7aaad07423..2de1eebe591f 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -27,6 +27,7 @@ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/seq_file.h> +#include <linux/iopoll.h> #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> @@ -3368,11 +3369,11 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, { int ret; - port = drm_dp_mst_topology_get_port_validated(mgr, port); - if (!port) + if (slots < 0) return false; - if (slots < 0) + port = drm_dp_mst_topology_get_port_validated(mgr, port); + if (!port) return false; if (port->vcpi.vcpi > 0) { @@ -3388,6 +3389,7 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, if (ret) { DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), ret); + drm_dp_mst_topology_put_port(port); goto out; } DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n", @@ -3498,6 +3500,17 @@ fail: return ret; } +static int do_get_act_status(struct drm_dp_aux *aux) +{ + int ret; + u8 status; + + ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); + if (ret < 0) + return ret; + + return status; +} /** * drm_dp_check_act_status() - Check ACT handled status. @@ -3507,33 +3520,29 @@ fail: */ int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) { - u8 status; - int ret; - int count = 0; - - do { - ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); - - if (ret < 0) { - DRM_DEBUG_KMS("failed to read payload table status %d\n", ret); - goto fail; - } - - if (status & DP_PAYLOAD_ACT_HANDLED) - break; - count++; - udelay(100); - - } while (count < 30); - - if (!(status & DP_PAYLOAD_ACT_HANDLED)) { - DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count); - ret = -EINVAL; - goto fail; + /* + * There doesn't seem to be any recommended retry count or timeout in + * the MST specification. Since some hubs have been observed to take + * over 1 second to update their payload allocations under certain + * conditions, we use a rather large timeout value. + */ + const int timeout_ms = 3000; + int ret, status; + + ret = readx_poll_timeout(do_get_act_status, mgr->aux, status, + status & DP_PAYLOAD_ACT_HANDLED || status < 0, + 200, timeout_ms * USEC_PER_MSEC); + if (ret < 0 && status >= 0) { + DRM_DEBUG_KMS("Failed to get ACT after %dms, last status: %02x\n", + timeout_ms, status); + return -EINVAL; + } else if (status < 0) { + DRM_DEBUG_KMS("Failed to read payload table status: %d\n", + status); + return status; } + return 0; -fail: - return ret; } EXPORT_SYMBOL(drm_dp_check_act_status); |