On Wed, 07 Jul 2021, Lee Shawn C <shawn.c....@intel.com> wrote: > Refer to DP link CTS 1.2/1.4 spec, the following test case request > source read DPCD 200h - 205h to get latest link status from sink. > > (4.3.2.4) Handling of IRQ HPD Pulse with No Error Status Bits Set > (400.3.2.1) Successful Link Re-training After IRQ HPD Pulse > Due to Loss of Symbol Lock: HBR2 Extension > (400.3.2.2) Successful Link Re-training After IRQ HPD Pulse Due > to Loss of Clock Recovery Lock: HBR2 Extension > (400.3.2.3) Successful Link Re-training After IRQ HPD Pulse Due > to Loss of Inter-lane Alignment Lock: HBR2 Extension > > So far, DRM DP driver just read back the link status from 202h > to 207h. DPR-120 would judge source can't pass these cases and > shows below error messages. > > "Test FAILED, Source DUT does not read DPCD registers 200h-205h > within 100 ms".
Acked-by: Jani Nikula <jani.nik...@intel.com> for making the test pass iff everything else seems to work. The underlying question is, though, should we look at 0x200-0x201 for some status we don't look at? > > v2: Use sizeof() to retrieve array size. > > Cc: Jani Nikula <jani.nik...@intel.com> > Cc: Ville Syrjälä <ville.syrj...@linux.intel.com> > Cc: Lyude Paul <ly...@redhat.com> > Cc: Simon Ser <cont...@emersion.fr> > Cc: Cooper Chiou <cooper.ch...@intel.com> > Cc: William Tseng <william.ts...@intel.com> > Signed-off-by: Lee Shawn C <shawn.c....@intel.com> > --- > drivers/gpu/drm/drm_dp_helper.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index 24bbc710c825..4f03df317d62 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -410,17 +410,19 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux > *aux, > u8 link_status[DP_LINK_STATUS_SIZE]) > { > int ret; > + u8 full_link_stat[DP_LINK_STATUS_SIZE + 2]; > > if (dp_phy == DP_PHY_DPRX) { > ret = drm_dp_dpcd_read(aux, > - DP_LANE0_1_STATUS, > - link_status, > - DP_LINK_STATUS_SIZE); > + DP_SINK_COUNT, > + full_link_stat, > + sizeof(full_link_stat)); > > if (ret < 0) > return ret; > > - WARN_ON(ret != DP_LINK_STATUS_SIZE); > + memcpy(link_status, full_link_stat + 2, DP_LINK_STATUS_SIZE); > + WARN_ON(ret != DP_LINK_STATUS_SIZE + 2); > > return 0; > } -- Jani Nikula, Intel Open Source Graphics Center