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From 43aefd39dbea27c0f6e238ed519f90946fc1e78b Mon Sep 17 00:00:00 2001
From: Nikola Cornij <nikola.cornij@amd.com>
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 <nikola.cornij@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
---
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
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