From 43aefd39dbea27c0f6e238ed519f90946fc1e78b Mon Sep 17 00:00:00 2001 From: Nikola Cornij Date: Wed, 9 May 2018 17:07:36 -0400 Subject: [PATCH 4540/5725] drm/amd/display: Optimize DP_SINK_STATUS_ESI range read on HPD DP_SINK_STATUS_ESI range data is not continual, but rather than getting it in two AUX reads, it's quicker to read more bytes in a AUX read and then memcpy the required fields (it's only 8 more bytes to read). Signed-off-by: Nikola Cornij Reviewed-by: Tony Cheng Acked-by: Harry Wentland --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index 9b66634..72a8a55 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -1647,22 +1647,26 @@ static enum dc_status read_hpd_rx_irq_data( irq_data->raw, sizeof(union hpd_irq_data)); else { - /* Read 2 bytes at this location,... */ + /* Read 14 bytes in a single read and then copy only the required fields. + * This is more efficient than doing it in two separate AUX reads. */ + + uint8_t tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI + 1]; + retval = core_link_read_dpcd( link, DP_SINK_COUNT_ESI, - irq_data->raw, - 2); + tmp, + sizeof(tmp)); if (retval != DC_OK) return retval; - /* ... then read remaining 4 at the other location */ - retval = core_link_read_dpcd( - link, - DP_LANE0_1_STATUS_ESI, - &irq_data->raw[2], - 4); + irq_data->bytes.sink_cnt.raw = tmp[DP_SINK_COUNT_ESI - DP_SINK_COUNT_ESI]; + irq_data->bytes.device_service_irq.raw = tmp[DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0 - DP_SINK_COUNT_ESI]; + irq_data->bytes.lane01_status.raw = tmp[DP_LANE0_1_STATUS_ESI - DP_SINK_COUNT_ESI]; + irq_data->bytes.lane23_status.raw = tmp[DP_LANE2_3_STATUS_ESI - DP_SINK_COUNT_ESI]; + irq_data->bytes.lane_status_updated.raw = tmp[DP_LANE_ALIGN_STATUS_UPDATED_ESI - DP_SINK_COUNT_ESI]; + irq_data->bytes.sink_status.raw = tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI]; } return retval; -- 2.7.4