| Message ID | 20210509044330.4655-1-pauldzim@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC] Revert "drm/i915: Try to use fast+narrow link on eDP again and fall back to the old max strategy on failure" | expand |
On Sat, May 8, 2021 at 9:44 PM Paul Zimmerman <pauldzim@gmail.com> wrote: > > This reverts commit 2bbd6dba84d44219387df051a1c799b7bac46099. > > Since 5.12-rc2, my Dell XPS-15 laptop has had a blank screen on boot. > The system seems to run fine other than having no display, I am able > to ssh into the machine. I don't see anything interesting in the dmesg > log. I bisected the problem down to this commit, and reverting it fixes > the problem. > > Signed-off-by: Paul Zimmerman <pauldzim@gmail.com> Replying to myself, to say that I just tested kernel 5.13-rc1, and the problem still exists there, and the same revert fixes the problem. - Paul > --- > I am attaching the dmesg log from 5.12.0 when the problem occurs. Any > other debugging info you want me to provide? > > .../drm/i915/display/intel_display_types.h | 1 - > drivers/gpu/drm/i915/display/intel_dp.c | 75 +++---------------- > 2 files changed, 9 insertions(+), 67 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index 184ecbbcec99..196900100689 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -1424,7 +1424,6 @@ struct intel_dp { > bool has_hdmi_sink; > bool has_audio; > bool reset_link_params; > - bool use_max_params; > u8 dpcd[DP_RECEIVER_CAP_SIZE]; > u8 psr_dpcd[EDP_PSR_RECEIVER_CAP_SIZE]; > u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]; > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > index 775d89b6c3fc..238ae1099132 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -480,13 +480,6 @@ int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, > return -1; > } > > - if (intel_dp_is_edp(intel_dp) && !intel_dp->use_max_params) { > - drm_dbg_kms(&i915->drm, > - "Retrying Link training for eDP with max parameters\n"); > - intel_dp->use_max_params = true; > - return 0; > - } > - > index = intel_dp_rate_index(intel_dp->common_rates, > intel_dp->num_common_rates, > link_rate); > @@ -1174,44 +1167,6 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp, > return -EINVAL; > } > > -/* Optimize link config in order: max bpp, min lanes, min clock */ > -static int > -intel_dp_compute_link_config_fast(struct intel_dp *intel_dp, > - struct intel_crtc_state *pipe_config, > - const struct link_config_limits *limits) > -{ > - const struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode; > - int bpp, clock, lane_count; > - int mode_rate, link_clock, link_avail; > - > - for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) { > - int output_bpp = intel_dp_output_bpp(pipe_config->output_format, bpp); > - > - mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock, > - output_bpp); > - > - for (lane_count = limits->min_lane_count; > - lane_count <= limits->max_lane_count; > - lane_count <<= 1) { > - for (clock = limits->min_clock; clock <= limits->max_clock; clock++) { > - link_clock = intel_dp->common_rates[clock]; > - link_avail = intel_dp_max_data_rate(link_clock, > - lane_count); > - > - if (mode_rate <= link_avail) { > - pipe_config->lane_count = lane_count; > - pipe_config->pipe_bpp = bpp; > - pipe_config->port_clock = link_clock; > - > - return 0; > - } > - } > - } > - } > - > - return -EINVAL; > -} > - > static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc) > { > int i, num_bpc; > @@ -1435,14 +1390,13 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, > limits.min_bpp = intel_dp_min_bpp(pipe_config->output_format); > limits.max_bpp = intel_dp_max_bpp(intel_dp, pipe_config); > > - if (intel_dp->use_max_params) { > + if (intel_dp_is_edp(intel_dp)) { > /* > * Use the maximum clock and number of lanes the eDP panel > - * advertizes being capable of in case the initial fast > - * optimal params failed us. The panels are generally > + * advertizes being capable of. The panels are generally > * designed to support only a single clock and lane > - * configuration, and typically on older panels these > - * values correspond to the native resolution of the panel. > + * configuration, and typically these values correspond to the > + * native resolution of the panel. > */ > limits.min_lane_count = limits.max_lane_count; > limits.min_clock = limits.max_clock; > @@ -1461,22 +1415,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, > intel_dp_can_bigjoiner(intel_dp)) > pipe_config->bigjoiner = true; > > - if (intel_dp_is_edp(intel_dp)) > - /* > - * Optimize for fast and narrow. eDP 1.3 section 3.3 and eDP 1.4 > - * section A.1: "It is recommended that the minimum number of > - * lanes be used, using the minimum link rate allowed for that > - * lane configuration." > - * > - * Note that we fall back to the max clock and lane count for eDP > - * panels that fail with the fast optimal settings (see > - * intel_dp->use_max_params), in which case the fast vs. wide > - * choice doesn't matter. > - */ > - ret = intel_dp_compute_link_config_fast(intel_dp, pipe_config, &limits); > - else > - /* Optimize for slow and wide. */ > - ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits); > + /* > + * Optimize for slow and wide. This is the place to add alternative > + * optimization policy. > + */ > + ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits); > > /* enable compression if the mode doesn't fit available BW */ > drm_dbg_kms(&i915->drm, "Force DSC en = %d\n", intel_dp->force_dsc_en); > -- > 2.25.1
On 9.5.2021 7.43, Paul Zimmerman wrote: > This reverts commit 2bbd6dba84d44219387df051a1c799b7bac46099. > > Since 5.12-rc2, my Dell XPS-15 laptop has had a blank screen on boot. > The system seems to run fine other than having no display, I am able > to ssh into the machine. I don't see anything interesting in the dmesg > log. I bisected the problem down to this commit, and reverting it fixes > the problem. Have you tried with drm-tip? It has acca7762eb71bc0 which hopefully helps here.
On Mon, May 10, 2021 at 7:00 AM Timo Aaltonen <tjaalton@ubuntu.com> wrote: > > On 9.5.2021 7.43, Paul Zimmerman wrote: > > This reverts commit 2bbd6dba84d44219387df051a1c799b7bac46099. > > > > Since 5.12-rc2, my Dell XPS-15 laptop has had a blank screen on boot. > > The system seems to run fine other than having no display, I am able > > to ssh into the machine. I don't see anything interesting in the dmesg > > log. I bisected the problem down to this commit, and reverting it fixes > > the problem. > > Have you tried with drm-tip? It has acca7762eb71bc0 which hopefully > helps here. I picked that one commit from the drm-tip tree (wasn't sure how to merge the entire tree into the kernel) and can confirm that it does fix the problem. Thank you! I hope the fix will be sent to Linus pretty soon, and it will need backporting to the 5.12 kernel as well. - Paul
On Mon, 10 May 2021, Paul Zimmerman <pauldzim@gmail.com> wrote: > On Mon, May 10, 2021 at 7:00 AM Timo Aaltonen <tjaalton@ubuntu.com> wrote: >> >> On 9.5.2021 7.43, Paul Zimmerman wrote: >> > This reverts commit 2bbd6dba84d44219387df051a1c799b7bac46099. >> > >> > Since 5.12-rc2, my Dell XPS-15 laptop has had a blank screen on boot. >> > The system seems to run fine other than having no display, I am able >> > to ssh into the machine. I don't see anything interesting in the dmesg >> > log. I bisected the problem down to this commit, and reverting it fixes >> > the problem. >> >> Have you tried with drm-tip? It has acca7762eb71bc0 which hopefully >> helps here. > > I picked that one commit from the drm-tip tree (wasn't sure how to merge > the entire tree into the kernel) and can confirm that it does fix the problem. > Thank you! I hope the fix will be sent to Linus pretty soon, and it will need > backporting to the 5.12 kernel as well. I've picked up 2bbd6dba84d4 ("drm/i915: Try to use fast+narrow link on eDP again and fall back to the old max strategy on failure") to drm-intel-fixes, and it should find itself in v5.13-rc2 and subsequently v5.12 stable in the coming weeks. BR, Jani.
On Tue, 11 May 2021, Jani Nikula <jani.nikula@linux.intel.com> wrote: > On Mon, 10 May 2021, Paul Zimmerman <pauldzim@gmail.com> wrote: >> On Mon, May 10, 2021 at 7:00 AM Timo Aaltonen <tjaalton@ubuntu.com> wrote: >>> >>> On 9.5.2021 7.43, Paul Zimmerman wrote: >>> > This reverts commit 2bbd6dba84d44219387df051a1c799b7bac46099. >>> > >>> > Since 5.12-rc2, my Dell XPS-15 laptop has had a blank screen on boot. >>> > The system seems to run fine other than having no display, I am able >>> > to ssh into the machine. I don't see anything interesting in the dmesg >>> > log. I bisected the problem down to this commit, and reverting it fixes >>> > the problem. >>> >>> Have you tried with drm-tip? It has acca7762eb71bc0 which hopefully >>> helps here. >> >> I picked that one commit from the drm-tip tree (wasn't sure how to merge >> the entire tree into the kernel) and can confirm that it does fix the problem. >> Thank you! I hope the fix will be sent to Linus pretty soon, and it will need >> backporting to the 5.12 kernel as well. > > I've picked up 2bbd6dba84d4 ("drm/i915: Try to use fast+narrow link on > eDP again and fall back to the old max strategy on failure") to > drm-intel-fixes, and it should find itself in v5.13-rc2 and subsequently > v5.12 stable in the coming weeks. I mean I've picked up acca7762eb71 ("drm/i915/dp: Use slow and wide link training for everything"). > > BR, > Jani.
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 184ecbbcec99..196900100689 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -1424,7 +1424,6 @@ struct intel_dp { bool has_hdmi_sink; bool has_audio; bool reset_link_params; - bool use_max_params; u8 dpcd[DP_RECEIVER_CAP_SIZE]; u8 psr_dpcd[EDP_PSR_RECEIVER_CAP_SIZE]; u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]; diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 775d89b6c3fc..238ae1099132 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -480,13 +480,6 @@ int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, return -1; } - if (intel_dp_is_edp(intel_dp) && !intel_dp->use_max_params) { - drm_dbg_kms(&i915->drm, - "Retrying Link training for eDP with max parameters\n"); - intel_dp->use_max_params = true; - return 0; - } - index = intel_dp_rate_index(intel_dp->common_rates, intel_dp->num_common_rates, link_rate); @@ -1174,44 +1167,6 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp, return -EINVAL; } -/* Optimize link config in order: max bpp, min lanes, min clock */ -static int -intel_dp_compute_link_config_fast(struct intel_dp *intel_dp, - struct intel_crtc_state *pipe_config, - const struct link_config_limits *limits) -{ - const struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode; - int bpp, clock, lane_count; - int mode_rate, link_clock, link_avail; - - for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) { - int output_bpp = intel_dp_output_bpp(pipe_config->output_format, bpp); - - mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock, - output_bpp); - - for (lane_count = limits->min_lane_count; - lane_count <= limits->max_lane_count; - lane_count <<= 1) { - for (clock = limits->min_clock; clock <= limits->max_clock; clock++) { - link_clock = intel_dp->common_rates[clock]; - link_avail = intel_dp_max_data_rate(link_clock, - lane_count); - - if (mode_rate <= link_avail) { - pipe_config->lane_count = lane_count; - pipe_config->pipe_bpp = bpp; - pipe_config->port_clock = link_clock; - - return 0; - } - } - } - } - - return -EINVAL; -} - static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc) { int i, num_bpc; @@ -1435,14 +1390,13 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, limits.min_bpp = intel_dp_min_bpp(pipe_config->output_format); limits.max_bpp = intel_dp_max_bpp(intel_dp, pipe_config); - if (intel_dp->use_max_params) { + if (intel_dp_is_edp(intel_dp)) { /* * Use the maximum clock and number of lanes the eDP panel - * advertizes being capable of in case the initial fast - * optimal params failed us. The panels are generally + * advertizes being capable of. The panels are generally * designed to support only a single clock and lane - * configuration, and typically on older panels these - * values correspond to the native resolution of the panel. + * configuration, and typically these values correspond to the + * native resolution of the panel. */ limits.min_lane_count = limits.max_lane_count; limits.min_clock = limits.max_clock; @@ -1461,22 +1415,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, intel_dp_can_bigjoiner(intel_dp)) pipe_config->bigjoiner = true; - if (intel_dp_is_edp(intel_dp)) - /* - * Optimize for fast and narrow. eDP 1.3 section 3.3 and eDP 1.4 - * section A.1: "It is recommended that the minimum number of - * lanes be used, using the minimum link rate allowed for that - * lane configuration." - * - * Note that we fall back to the max clock and lane count for eDP - * panels that fail with the fast optimal settings (see - * intel_dp->use_max_params), in which case the fast vs. wide - * choice doesn't matter. - */ - ret = intel_dp_compute_link_config_fast(intel_dp, pipe_config, &limits); - else - /* Optimize for slow and wide. */ - ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits); + /* + * Optimize for slow and wide. This is the place to add alternative + * optimization policy. + */ + ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits); /* enable compression if the mode doesn't fit available BW */ drm_dbg_kms(&i915->drm, "Force DSC en = %d\n", intel_dp->force_dsc_en);
This reverts commit 2bbd6dba84d44219387df051a1c799b7bac46099. Since 5.12-rc2, my Dell XPS-15 laptop has had a blank screen on boot. The system seems to run fine other than having no display, I am able to ssh into the machine. I don't see anything interesting in the dmesg log. I bisected the problem down to this commit, and reverting it fixes the problem. Signed-off-by: Paul Zimmerman <pauldzim@gmail.com> --- I am attaching the dmesg log from 5.12.0 when the problem occurs. Any other debugging info you want me to provide? .../drm/i915/display/intel_display_types.h | 1 - drivers/gpu/drm/i915/display/intel_dp.c | 75 +++---------------- 2 files changed, 9 insertions(+), 67 deletions(-)