[Intel-gfx] [RFC 7/7] drm/i915/dp: Program vswing, pre-emphasis, test-pattern
Manasi Navare
manasi.d.navare at intel.com
Tue Jan 14 21:38:31 UTC 2020
On Fri, Dec 13, 2019 at 10:54:20PM +0530, Animesh Manna wrote:
> Hi Manasi/Jani,
>
> Thanks for helping phy compliance design.
>
> Added my understanding/doubts below.
>
>
> On 12/12/2019 5:20 AM, Manasi Navare wrote:
> >Hi Animesh/Jani,
> >
> >Is this the right way to force a full modeset by adding new dev_priv->dp_phy_comp?
>
> In modeset path we disable active crtc first then initiate the modeset
> sequence which is causing trouble in updating phy compliance parameters in
> modeset path.
> As per phy compliance spec test-scope can request to change the following
> parameters,
> - Test pattern
> - V-swing:
> - Pre-emphasis:
> - Link rate:
> - Lane count:
>
> For test-pattern/v-swing/pre-emphasis, active link may not need to cut.
> Tried the same in the following patch series where I am skipping
> atomic-check, atomic-commit and write these parameters in atomic-commit-tail
> without touching anything else. Can you please share your thought how to
> handle it properly. Maybe once we are clear about what we should do in
> atomic_check/atomic_commit/atomic_commit_tail we can move dp_phy_comp flag
> to some atomic-state object.
> https://patchwork.freedesktop.org/series/70300/
So from what we had finalized on the call, was that the intel_dp_process_phy_request() would be
called in ddi_pre_enable_dp in case of dP PHY request for which you would need
to update needs_modeset() and set it to true if PHY compliance request.
That looked like a correct approach to me and AFAIR was agreed by Jani and Uma as well.
And that was decided so that this gets plugged into out atomic infrastructure.
Are you now suggesting that with that approach or the code in this patch, PHY compliance
tests for changing test-pattern/vswing/pre - emphasis are not working?
Why did you want to change the design to skip atomic check and atomic commit?
If we skip the atomic check and atomic commit and directly write these parameters in atomic commit tail
then we are essentially doing - 1. Get Short pulse, read DPCD, write the test parameters and not going
through atomic KMS ever.
And we will need to have another meeting to see if this will be accepted without going through atomic.
This might work if the PHY compliance does not expect any other crtc_state parameter change no
change in link rate/lane count or PLLs.
This brings us to our next discussion, where we need to confirm from PHY compliance Chrome team:
1. Does PHY Compliance test request require link training for requested link rate/lane count (There should be a box in
Software capabilities in DPR 100 they are using that will give this info) Clint here confimed that it does say
link training required
2. If link training required box checked, Chrome team needs to confirm if a link layer compliance request
is sent prior to every PHY request (from dmesg logs or DPR 100 logs)
3. If link layer comp request is set, then that should handle changing link rate and setting PLLs
4. In this case then we in PHY compliance do not needs to go through atomic check and commit we can
skip that and directly write the test patter/.vswing/pre-emaphasis and rather just call
the intel_dp_process_phy_request() directly on test req short pulse processing like your original design.
Animesh, please work on getting these clarifications from Chrome team and we can close
on these opens.
Meanwhile I am trying to get the DPR 100 and test equipment and do the testing myself here to
understand the flow.
Manasi
>
> For Link-rate/lane-count, we need to do link-training/modeset. As per my
> observation the request is coming as link-compliance request, still waiting
> feedback from compliance team to confirm. So not handled as part
> dp-phy-compliance implementation.
Yes we need to push the Chrome OS team to get clarification on this:
- Does PHY compliance req always send a link compliance request before requesting link rate/lane count change?
Once we get this clarification we will
> >Also its still not clear to me how this will work without actualling using the phy link rate
> >and lane count stored in the phy test pattern params to compute the pipe config?
> >Currently those only get used directly to set the link bw.
>
> If link-compliance request is not used for link-rate/lane-count change then
> your point is valid. As mentioned above getting link-compliance request
> which is confusing and waiting confirmation from compliance team.
>
> >This can work if the phy comp runs after link layer comp but on standalone phy comp testing
> >this could be a problem.
> >
> >Also I dont see my comment addressed where I had asked to move the below to patch 3:
> >>>+ /* Set test active flag here so userspace doesn't interrupt things */
> >>>+ intel_dp->compliance.test_active = 1;
> >>>+ dev_priv->dp_phy_comp = true;
> >>>+
>
> Thinking of creating a separate patch for sending uevent and setting
> test_active flag true for intel_dp_compliance tool.
> The patch 3/7 will take the preparation part and acknowledge the test
> request. Hope it will be fine.
>
> Regards,
> Animesh
>
> >Manasi
> >
> >
> >On Sun, Nov 17, 2019 at 11:53:54PM -0800, Manasi Navare wrote:
> >>On Fri, Nov 15, 2019 at 08:55:49PM +0530, Animesh Manna wrote:
> >>>This patch process phy compliance request by programming requested
> >>>vswing, pre-emphasis and test pattern.
> >>Again here a slightly detailed description of where in the atomic modeset
> >>do we process the PHY com request would be good.
> >>
> >>The design overall looks good now, few comments below:
> >>
> >>>Signed-off-by: Animesh Manna <animesh.manna at intel.com>
> >>>---
> >>> drivers/gpu/drm/i915/display/intel_ddi.c | 14 ++++
> >>> drivers/gpu/drm/i915/display/intel_display.c | 5 ++
> >>> drivers/gpu/drm/i915/display/intel_dp.c | 77 ++++++++++++++++++++
> >>> drivers/gpu/drm/i915/display/intel_dp.h | 2 +
> >>> drivers/gpu/drm/i915/i915_drv.h | 2 +
> >>> 5 files changed, 100 insertions(+)
> >>>
> >>>diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> >>>index 8f817de34460..c12d4ebbd352 100644
> >>>--- a/drivers/gpu/drm/i915/display/intel_ddi.c
> >>>+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> >>>@@ -3700,8 +3700,17 @@ static void intel_ddi_pre_enable(struct intel_encoder *encoder,
> >>> {
> >>> struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> >>> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> >>>+ struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
> >>> enum pipe pipe = crtc->pipe;
> >>>+ if (encoder->type == INTEL_OUTPUT_DP) {
> >>>+ if (dig_port->dp.compliance.test_type ==
> >>>+ DP_TEST_LINK_PHY_TEST_PATTERN) {
> >>>+ intel_dp_process_phy_request(&dig_port->dp);
> >>>+ return;
> >>>+ }
> >>>+ }
> >>>+
> >>> /*
> >>> * When called from DP MST code:
> >>> * - conn_state will be NULL
> >>>@@ -4147,6 +4156,11 @@ intel_ddi_pre_pll_enable(struct intel_encoder *encoder,
> >>> enum phy phy = intel_port_to_phy(dev_priv, encoder->port);
> >>> bool is_tc_port = intel_phy_is_tc(dev_priv, phy);
> >>>+ if (encoder->type == INTEL_OUTPUT_DP)
> >>>+ if (dig_port->dp.compliance.test_type ==
> >>>+ DP_TEST_LINK_PHY_TEST_PATTERN)
> >>>+ return;
> >>>+
> >>> if (is_tc_port)
> >>> intel_tc_port_get_link(dig_port, crtc_state->lane_count);
> >>>diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> >>>index adf50c4b38ad..4ad11df55f07 100644
> >>>--- a/drivers/gpu/drm/i915/display/intel_display.c
> >>>+++ b/drivers/gpu/drm/i915/display/intel_display.c
> >>>@@ -545,6 +545,11 @@ icl_wa_scalerclkgating(struct drm_i915_private *dev_priv, enum pipe pipe,
> >>> static bool
> >>> needs_modeset(const struct intel_crtc_state *state)
> >>> {
> >>>+ struct drm_i915_private *dev_priv = to_i915(state->uapi.crtc->dev);
> >>>+
> >>>+ if (dev_priv->dp_phy_comp)
> >>>+ return true;
> >>Could you double check with Jani N if this is an acceptable solution to
> >>foce a full modeset for a PHY compliance test?
> >>
> >>>+
> >>> return drm_atomic_crtc_needs_modeset(&state->uapi);
> >>> }
> >>>diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> >>>index df31278a1619..2c3d4b6c6036 100644
> >>>--- a/drivers/gpu/drm/i915/display/intel_dp.c
> >>>+++ b/drivers/gpu/drm/i915/display/intel_dp.c
> >>>@@ -5010,14 +5010,91 @@ static inline void intel_dp_phy_pattern_update(struct intel_dp *intel_dp)
> >>> }
> >>> }
> >>>+static void
> >>>+intel_dp_autotest_phy_ddi_disable(struct intel_dp *intel_dp)
> >>>+{
> >>>+ struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> >>>+ struct drm_device *dev = intel_dig_port->base.base.dev;
> >>>+ struct drm_i915_private *dev_priv = to_i915(dev);
> >>>+ enum port port = intel_dig_port->base.port;
> >>>+ u32 ddi_buf_ctl_value, dp_tp_ctl_value, trans_ddi_func_ctl_value;
> >>>+
> >>>+ ddi_buf_ctl_value = I915_READ(DDI_BUF_CTL(port));
> >>>+ dp_tp_ctl_value = I915_READ(TGL_DP_TP_CTL(port));
> >>>+ trans_ddi_func_ctl_value = I915_READ(TRANS_DDI_FUNC_CTL(port));
> >>>+
> >>>+ ddi_buf_ctl_value &= ~(DDI_BUF_CTL_ENABLE | DDI_PORT_WIDTH_MASK);
> >>>+ dp_tp_ctl_value &= ~DP_TP_CTL_ENABLE;
> >>>+ trans_ddi_func_ctl_value &= ~(TRANS_DDI_FUNC_ENABLE |
> >>>+ DDI_PORT_WIDTH_MASK);
> >>>+
> >>>+ I915_WRITE(DDI_BUF_CTL(port), ddi_buf_ctl_value);
> >>>+ I915_WRITE(TGL_DP_TP_CTL(port), dp_tp_ctl_value);
> >>>+ I915_WRITE(TRANS_DDI_FUNC_CTL(port), trans_ddi_func_ctl_value);
> >>>+}
> >>>+
> >>>+static void
> >>>+intel_dp_autotest_phy_ddi_enable(struct intel_dp *intel_dp, uint8_t lane_cnt)
> >>>+{
> >>>+ struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> >>>+ struct drm_device *dev = intel_dig_port->base.base.dev;
> >>>+ struct drm_i915_private *dev_priv = to_i915(dev);
> >>>+ enum port port = intel_dig_port->base.port;
> >>>+ u32 ddi_buf_ctl_value, dp_tp_ctl_value, trans_ddi_func_ctl_value;
> >>>+
> >>>+ ddi_buf_ctl_value = I915_READ(DDI_BUF_CTL(port));
> >>>+ dp_tp_ctl_value = I915_READ(TGL_DP_TP_CTL(port));
> >>>+ trans_ddi_func_ctl_value = I915_READ(TRANS_DDI_FUNC_CTL(port));
> >>>+
> >>>+ ddi_buf_ctl_value |= DDI_BUF_CTL_ENABLE |
> >>>+ DDI_PORT_WIDTH(lane_cnt);
> >>>+ dp_tp_ctl_value |= DP_TP_CTL_ENABLE;
> >>>+ trans_ddi_func_ctl_value |= TRANS_DDI_FUNC_ENABLE |
> >>>+ DDI_PORT_WIDTH(lane_cnt);
> >>>+
> >>>+ I915_WRITE(TRANS_DDI_FUNC_CTL(port), trans_ddi_func_ctl_value);
> >>>+ I915_WRITE(TGL_DP_TP_CTL(port), dp_tp_ctl_value);
> >>>+ I915_WRITE(DDI_BUF_CTL(port), ddi_buf_ctl_value);
> >>>+}
> >>>+
> >>>+void intel_dp_process_phy_request(struct intel_dp *intel_dp)
> >>>+{
> >>>+ struct drm_dp_phy_test_params *data =
> >>>+ &intel_dp->compliance.test_data.phytest;
> >>>+ u8 link_status[DP_LINK_STATUS_SIZE];
> >>>+
> >>>+ if (!intel_dp_get_link_status(intel_dp, link_status)) {
> >>>+ DRM_DEBUG_KMS("failed to get link status\n");
> >>>+ return;
> >>>+ }
> >>>+
> >>>+ /* retrieve vswing & pre-emphasis setting */
> >>>+ intel_get_adjust_train(intel_dp, link_status);
> >>>+
> >>>+ intel_dp_autotest_phy_ddi_disable(intel_dp);
> >>>+
> >>>+ intel_dp_set_signal_levels(intel_dp);
> >>>+
> >>>+ intel_dp_phy_pattern_update(intel_dp);
> >>>+
> >>>+ intel_dp_autotest_phy_ddi_enable(intel_dp, data->num_lanes);
> >>>+
> >>>+ drm_dp_set_phy_test_pattern(&intel_dp->aux, data);
> >>>+}
> >>>+
> >>> static u8 intel_dp_autotest_phy_pattern(struct intel_dp *intel_dp)
> >>> {
> >>> u8 test_result = DP_TEST_NAK;
> >>>+ struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> >>> test_result = intel_dp_prepare_phytest(intel_dp);
> >>> if (test_result != DP_TEST_ACK)
> >>> DRM_ERROR("Phy test preparation failed\n");
> >>>+ /* Set test active flag here so userspace doesn't interrupt things */
> >>>+ intel_dp->compliance.test_active = 1;
> >>>+ dev_priv->dp_phy_comp = true;
> >>>+
> >>This should be moved to the patch 3 I think where you handle phy test request and
> >>call prepare function. The same patch that handles test req can set the test active to 1.
> >>
> >>> return test_result;
> >>> }
> >>>diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
> >>>index 0d0cb692f701..b1274ecffc7f 100644
> >>>--- a/drivers/gpu/drm/i915/display/intel_dp.h
> >>>+++ b/drivers/gpu/drm/i915/display/intel_dp.h
> >>>@@ -120,6 +120,8 @@ void intel_dp_hdr_metadata_enable(struct intel_dp *intel_dp,
> >>> const struct intel_crtc_state *crtc_state,
> >>> const struct drm_connector_state *conn_state);
> >>> bool intel_digital_port_connected(struct intel_encoder *encoder);
> >>>+void intel_dp_process_phy_request(struct intel_dp *intel_dp);
> >>>+
> >>> static inline unsigned int intel_dp_unused_lane_mask(int lane_count)
> >>> {
> >>>diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> >>>index 1779f600fcfb..232e0dfb9d8e 100644
> >>>--- a/drivers/gpu/drm/i915/i915_drv.h
> >>>+++ b/drivers/gpu/drm/i915/i915_drv.h
> >>>@@ -1285,6 +1285,8 @@ struct drm_i915_private {
> >>> I915_SELFTEST_DECLARE(struct i915_selftest_stash selftest;)
> >>>+ bool dp_phy_comp;
> >>Not sure if this is the best way to handle the full mdoeset, could you double
> >>check with Jani?
> >>
> >>Other than that I think now the placement in pre_enable_dp is good.
> >>
> >>The only other concern I have is changing link rate and lane count only happens
> >>in set_phy_patterns where we write the test link rate and lane count
> >>directly to the link bw set. But the driver's compute config is still configuring
> >>the pipe and plls based on the link rate and lane count that could be
> >>different than the test link rate/count. This might work now since you said
> >>the link layer test is already configuring it at test params but in general
> >>shouldnt we be using the phy->link rate and lane count if in phy compliance
> >>also in compute_config()?
> >>
> >>Jani, any thoughts here?
> >>
> >>Regards
> >>Manasi
> >>
> >>>+
> >>> /*
> >>> * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
> >>> * will be rejected. Instead look for a better place.
> >>>--
> >>>2.22.0
> >>>
> >>_______________________________________________
> >>Intel-gfx mailing list
> >>Intel-gfx at lists.freedesktop.org
> >>https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
More information about the Intel-gfx
mailing list