From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 22 Jan 2018 19:41:31 +0200 Subject: drm/i915: Implement display w/a #1143 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Git-commit: 0519c102f5285476d7868a387bdb6c58385e4074 Patch-mainline: v4.17-rc1 References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166 Apparently SKL/KBL/CFL need some manual help to get the programmed HDMI vswing to stick. Implement the relevant workaround (display w/a #1143). Note that the relevant chicken bits live in a transcoder register even though the bits affect a specific DDI port rather than a specific transcoder. Hence we must pick the correct transcoder register instance based on the port rather than based on the cpu_transcoder. Also note that for completeness I included support for DDI A/E in the code even though we never have HDMI on those ports. v2: CFL needs the w/a as well (Rodrigo and Art) Cc: Rodrigo Vivi Cc: Art Runyan Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180122174131.28046-1-ville.syrjala@linux.intel.com Reviewed-by: Rodrigo Vivi Acked-by: Petr Tesarik --- drivers/gpu/drm/i915/i915_reg.h | 8 +++++-- drivers/gpu/drm/i915/intel_ddi.c | 42 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -7079,8 +7079,12 @@ enum { #define CHICKEN_TRANS_A 0x420c0 #define CHICKEN_TRANS_B 0x420c4 #define CHICKEN_TRANS(trans) _MMIO_TRANS(trans, CHICKEN_TRANS_A, CHICKEN_TRANS_B) -#define PSR2_VSC_ENABLE_PROG_HEADER (1<<12) -#define PSR2_ADD_VERTICAL_LINE_COUNT (1<<15) +#define DDI_TRAINING_OVERRIDE_ENABLE (1<<19) +#define DDI_TRAINING_OVERRIDE_VALUE (1<<18) +#define DDIE_TRAINING_OVERRIDE_ENABLE (1<<17) /* CHICKEN_TRANS_A only */ +#define DDIE_TRAINING_OVERRIDE_VALUE (1<<16) /* CHICKEN_TRANS_A only */ +#define PSR2_ADD_VERTICAL_LINE_COUNT (1<<15) +#define PSR2_VSC_ENABLE_PROG_HEADER (1<<12) #define DISP_ARB_CTL _MMIO(0x45000) #define DISP_FBC_MEMORY_WAKE (1<<31) --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -2401,6 +2401,48 @@ static void intel_enable_ddi_hdmi(struct crtc_state->hdmi_high_tmds_clock_ratio, crtc_state->hdmi_scrambling); + /* Display WA #1143: skl,kbl,cfl */ + if (IS_GEN9_BC(dev_priv)) { + /* + * For some reason these chicken bits have been + * stuffed into a transcoder register, event though + * the bits affect a specific DDI port rather than + * a specific transcoder. + */ + static const enum transcoder port_to_transcoder[] = { + [PORT_A] = TRANSCODER_EDP, + [PORT_B] = TRANSCODER_A, + [PORT_C] = TRANSCODER_B, + [PORT_D] = TRANSCODER_C, + [PORT_E] = TRANSCODER_A, + }; + enum transcoder transcoder = port_to_transcoder[port]; + u32 val; + + val = I915_READ(CHICKEN_TRANS(transcoder)); + + if (port == PORT_E) + val |= DDIE_TRAINING_OVERRIDE_ENABLE | + DDIE_TRAINING_OVERRIDE_VALUE; + else + val |= DDI_TRAINING_OVERRIDE_ENABLE | + DDI_TRAINING_OVERRIDE_VALUE; + + I915_WRITE(CHICKEN_TRANS(transcoder), val); + POSTING_READ(CHICKEN_TRANS(transcoder)); + + udelay(1); + + if (port == PORT_E) + val &= ~(DDIE_TRAINING_OVERRIDE_ENABLE | + DDIE_TRAINING_OVERRIDE_VALUE); + else + val &= ~(DDI_TRAINING_OVERRIDE_ENABLE | + DDI_TRAINING_OVERRIDE_VALUE); + + I915_WRITE(CHICKEN_TRANS(transcoder), val); + } + /* In HDMI/DVI mode, the port width, and swing/emphasis values * are ignored so nothing special needs to be done besides * enabling the port.