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drm/i915: Implement display w/a #1143

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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 <rodrigo.vivi@intel.com>
Cc: Art Runyan <arthur.j.runyan@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180122174131.28046-1-ville.syrjala@linux.intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Ville Syrjälä 2018-01-22 19:41:31 +02:00
parent c19e1124e7
commit 0519c102f5
2 changed files with 48 additions and 2 deletions
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8
drivers/gpu/drm/i915/i915_reg.h
View file

@ -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)

42
drivers/gpu/drm/i915/intel_ddi.c
View file

@ -2404,6 +2404,48 @@ static void intel_enable_ddi_hdmi(struct intel_encoder *encoder,
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.