diff options
| author | Michael Strauss <michael.strauss@amd.com> | 2019-10-03 11:54:15 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-10-30 11:56:16 -0400 |
| commit | bc2fde42e2418808dbfc04de1a6da91d7d31cf1a (patch) | |
| tree | 12182fa5d1e27ac683ed3140b3b1e24450865737 /drivers/gpu/drm/amd/display | |
| parent | 7c37d399c2b84d4b79de4d512a38373f1d71ab90 (diff) | |
| download | linux-bc2fde42e2418808dbfc04de1a6da91d7d31cf1a.tar.bz2 | |
drm/amd/display: Passive DP->HDMI dongle detection fix
[WHY]
i2c_read is called to differentiate passive DP->HDMI and DP->DVI-D dongles
The call is expected to fail in DVI-D case but pass in HDMI case
Some HDMI dongles have a chance to fail as well, causing misdetection as DVI-D
[HOW]
Retry i2c_read to ensure failed result is valid
Signed-off-by: Michael Strauss <michael.strauss@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c index 505967b48e14..51991bf26a93 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c @@ -374,6 +374,7 @@ void dal_ddc_service_i2c_query_dp_dual_mode_adaptor( enum display_dongle_type *dongle = &sink_cap->dongle_type; uint8_t type2_dongle_buf[DP_ADAPTOR_TYPE2_SIZE]; bool is_type2_dongle = false; + int retry_count = 2; struct dp_hdmi_dongle_signature_data *dongle_signature; /* Assume we have no valid DP passive dongle connected */ @@ -386,13 +387,24 @@ void dal_ddc_service_i2c_query_dp_dual_mode_adaptor( DP_HDMI_DONGLE_ADDRESS, type2_dongle_buf, sizeof(type2_dongle_buf))) { - *dongle = DISPLAY_DONGLE_DP_DVI_DONGLE; - sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_DVI_MAX_TMDS_CLK; + /* Passive HDMI dongles can sometimes fail here without retrying*/ + while (retry_count > 0) { + if (i2c_read(ddc, + DP_HDMI_DONGLE_ADDRESS, + type2_dongle_buf, + sizeof(type2_dongle_buf))) + break; + retry_count--; + } + if (retry_count == 0) { + *dongle = DISPLAY_DONGLE_DP_DVI_DONGLE; + sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_DVI_MAX_TMDS_CLK; - CONN_DATA_DETECT(ddc->link, type2_dongle_buf, sizeof(type2_dongle_buf), - "DP-DVI passive dongle %dMhz: ", - DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000); - return; + CONN_DATA_DETECT(ddc->link, type2_dongle_buf, sizeof(type2_dongle_buf), + "DP-DVI passive dongle %dMhz: ", + DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000); + return; + } } /* Check if Type 2 dongle.*/ |