On Thu, 05 Sep 2024, Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx> wrote: > LINK_N register has bits 31:24 for extended link N value used for > HDMI2.1 and for an alternate mode of operation of DP TG DDA > (Bspec:50488). > > Add support for these extra bits. Please throw away the link_n_ext member, and go from there. Most of the changes here are unnecessary. Mask N after reading and before writing to 24 bits on older platforms, don't mask on display >= 14. That's all there is to it. BR, Jani. > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx> > --- > drivers/gpu/drm/i915/display/intel_display.c | 31 +++++++++++++++---- > .../drm/i915/display/intel_display_types.h | 1 + > drivers/gpu/drm/i915/i915_reg.h | 2 ++ > 3 files changed, 28 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > index b4ef4d59da1a..60cdd7a37b03 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.c > +++ b/drivers/gpu/drm/i915/display/intel_display.c > @@ -2595,6 +2595,8 @@ intel_link_compute_m_n(u16 bits_per_pixel_x16, int nlanes, > compute_m_n(&m_n->link_m, &m_n->link_n, > pixel_clock, link_symbol_clock, > 0x80000); > + > + m_n->link_n_ext = 0; > } > > void intel_panel_sanitize_ssc(struct drm_i915_private *dev_priv) > @@ -2632,6 +2634,7 @@ void intel_set_m_n(struct drm_i915_private *i915, > i915_reg_t data_m_reg, i915_reg_t data_n_reg, > i915_reg_t link_m_reg, i915_reg_t link_n_reg) > { > + u8 link_n_ext = 0; > intel_de_write(i915, data_m_reg, TU_SIZE(m_n->tu) | m_n->data_m); > intel_de_write(i915, data_n_reg, m_n->data_n); > intel_de_write(i915, link_m_reg, m_n->link_m); > @@ -2639,7 +2642,11 @@ void intel_set_m_n(struct drm_i915_private *i915, > * On BDW+ writing LINK_N arms the double buffered update > * of all the M/N registers, so it must be written last. > */ > - intel_de_write(i915, link_n_reg, m_n->link_n); > + > + if (DISPLAY_VER(i915) >= 14 && m_n->link_n_ext) > + link_n_ext = PIPE_LINK_N1_EXTENDED(m_n->link_n_ext); > + > + intel_de_write(i915, link_n_reg, m_n->link_n | link_n_ext); > } > > bool intel_cpu_transcoder_has_m2_n2(struct drm_i915_private *dev_priv, > @@ -3346,8 +3353,17 @@ void intel_get_m_n(struct drm_i915_private *i915, > i915_reg_t data_m_reg, i915_reg_t data_n_reg, > i915_reg_t link_m_reg, i915_reg_t link_n_reg) > { > + u32 link_n; > + > m_n->link_m = intel_de_read(i915, link_m_reg) & DATA_LINK_M_N_MASK; > - m_n->link_n = intel_de_read(i915, link_n_reg) & DATA_LINK_M_N_MASK; > + > + link_n = intel_de_read(i915, link_n_reg); > + m_n->link_n = link_n & DATA_LINK_M_N_MASK; > + if (DISPLAY_VER(i915) >= 14) > + m_n->link_n_ext = REG_FIELD_GET(PIPE_LINK_N1_EXTENDED_MASK, link_n); > + else > + m_n->link_n_ext = 0; > + > m_n->data_m = intel_de_read(i915, data_m_reg) & DATA_LINK_M_N_MASK; > m_n->data_n = intel_de_read(i915, data_n_reg) & DATA_LINK_M_N_MASK; > m_n->tu = REG_FIELD_GET(TU_SIZE_MASK, intel_de_read(i915, data_m_reg)) + 1; > @@ -4843,7 +4859,8 @@ intel_compare_link_m_n(const struct intel_link_m_n *m_n, > m_n->data_m == m2_n2->data_m && > m_n->data_n == m2_n2->data_n && > m_n->link_m == m2_n2->link_m && > - m_n->link_n == m2_n2->link_n; > + m_n->link_n == m2_n2->link_n && > + m_n->link_n_ext == m2_n2->link_n_ext; > } > > static bool > @@ -5133,18 +5150,20 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config, > if (!intel_compare_link_m_n(¤t_config->name, \ > &pipe_config->name)) { \ > pipe_config_mismatch(&p, fastset, crtc, __stringify(name), \ > - "(expected tu %i data %i/%i link %i/%i, " \ > - "found tu %i, data %i/%i link %i/%i)", \ > + "(expected tu %i data %i/%i link %i/%i link_n_ext %i, " \ > + "found tu %i, data %i/%i link %i/%i link_n_ext %i)", \ > current_config->name.tu, \ > current_config->name.data_m, \ > current_config->name.data_n, \ > current_config->name.link_m, \ > current_config->name.link_n, \ > + current_config->name.link_n_ext, \ > pipe_config->name.tu, \ > pipe_config->name.data_m, \ > pipe_config->name.data_n, \ > pipe_config->name.link_m, \ > - pipe_config->name.link_n); \ > + pipe_config->name.link_n, \ > + pipe_config->name.link_n_ext); \ > ret = false; \ > } \ > } while (0) > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index f29e5dc3db91..1328e2e89786 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -1028,6 +1028,7 @@ struct intel_link_m_n { > u32 data_n; > u32 link_m; > u32 link_n; > + u8 link_n_ext; > }; > > struct intel_csc_matrix { > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h > index 41f4350a7c6c..941d273dbf8c 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -2172,6 +2172,8 @@ > #define _PIPEB_DATA_N2 0x6103c > #define _PIPEB_LINK_M1 0x61040 > #define _PIPEB_LINK_N1 0x61044 > +#define PIPE_LINK_N1_EXTENDED_MASK REG_GENMASK(31, 24) > +#define PIPE_LINK_N1_EXTENDED(val) REG_FIELD_PREP(PIPE_LINK_N1_EXTENDED_MASK, (val)) > #define _PIPEB_LINK_M2 0x61048 > #define _PIPEB_LINK_N2 0x6104c -- Jani Nikula, Intel