HW revision is mandatory field for DisplayPort branch devices. This is defined in DPCD register field 0x509.
Signed-off-by: Mika Kahola <mika.kahola at intel.com> --- drivers/gpu/drm/i915/intel_dp.c | 5 +++++ include/drm/drm_dp_helper.h | 2 ++ 2 files changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 2b768da..12ab26b 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3463,6 +3463,11 @@ intel_dp_probe_oui(struct intel_dp *intel_dp) if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_ID, intel_dp->bd.id, sizeof(intel_dp->bd.id)) == sizeof(intel_dp->bd.id)) DRM_DEBUG_KMS("Device ID: %s\n", intel_dp->bd.id); + + if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_HW_REV, &intel_dp->bd.hw_rev, + sizeof(intel_dp->bd.hw_rev)) == sizeof(intel_dp->bd.hw_rev)) + DRM_DEBUG_KMS("HW revision: %.2d.%.2d\n", + intel_dp->bd.hw_rev & 0xf, (intel_dp->bd.hw_rev>>4) & 0xf); } } diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index f1fc4e2..d0965ca 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -458,6 +458,7 @@ #define DP_SINK_OUI 0x400 #define DP_BRANCH_OUI 0x500 #define DP_BRANCH_ID 0x503 +#define DP_BRANCH_HW_REV 0x509 #define DP_SET_POWER 0x600 # define DP_SET_POWER_D0 0x1 @@ -871,6 +872,7 @@ struct drm_dp_bd { int type; bool hpd; uint8_t id[6]; + uint8_t hw_rev; union { struct drm_dp_vga vga; struct drm_dp_dvi dvi; -- 1.9.1