[Intel-gfx] [PATCH v3] drm/i915/display: Fix the 12 BPC bits for PIPE_MISC reg
Shankar, Uma
uma.shankar at intel.com
Wed Aug 11 13:19:13 UTC 2021
> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Shankar,
> Uma
> Sent: Wednesday, August 11, 2021 11:39 AM
> To: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>; intel-gfx at lists.freedesktop.org
> Cc: Zanoni, Paulo R <paulo.r.zanoni at intel.com>; ville.syrjala at linux.intel.com;
> daniel.vetter at ffwll.ch; jani.nikula at linux.intel.com;
> joonas.lahtinen at linux.intel.com; Vivi, Rodrigo <rodrigo.vivi at intel.com>;
> stable at vger.kernel.org
> Subject: Re: [Intel-gfx] [PATCH v3] drm/i915/display: Fix the 12 BPC bits for
> PIPE_MISC reg
>
Change pushed to drm-intel-next. Thanks for the patch.
Regards,
Uma Shankar
>
> > -----Original Message-----
> > From: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>
> > Sent: Wednesday, August 11, 2021 10:49 AM
> > To: intel-gfx at lists.freedesktop.org
> > Cc: Shankar, Uma <uma.shankar at intel.com>; Zanoni, Paulo R
> > <paulo.r.zanoni at intel.com>; ville.syrjala at linux.intel.com;
> > daniel.vetter at ffwll.ch; jani.nikula at linux.intel.com;
> > joonas.lahtinen at linux.intel.com; Vivi, Rodrigo
> > <rodrigo.vivi at intel.com>; stable at vger.kernel.org; Nautiyal, Ankit K
> > <ankit.k.nautiyal at intel.com>
> > Subject: [PATCH v3] drm/i915/display: Fix the 12 BPC bits for
> > PIPE_MISC reg
> >
> > Till DISPLAY12 the PIPE_MISC bits 5-7 are used to set the Dithering
> > BPC, with valid values of 6, 8, 10 BPC.
> > For ADLP+ these bits are used to set the PORT OUTPUT BPC, with valid
> > values of: 6, 8, 10, 12 BPC, and need to be programmed whether dithering is
> enabled or not.
> >
> > This patch:
> > -corrects the bits 5-7 for PIPE MISC register for 12 BPC.
> > -renames the bits and mask to have generic names for these bits for
> > dithering bpc and port output bpc.
> >
> > v3: Added a note for MIPI DSI which uses the PIPE_MISC for readout for pipe_bpp.
> > (Uma Shankar)
> >
> > v2: Added 'display' to the subject and fixes tag. (Uma Shankar)
> >
>
> Looks Good to me.
> Reviewed-by: Uma Shankar <uma.shankar at intel.com>
>
> > Fixes: 756f85cffef2 ("drm/i915/bdw: Broadwell has PIPEMISC")
> > Cc: Paulo Zanoni <paulo.r.zanoni at intel.com> (v1)
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Cc: Jani Nikula <jani.nikula at linux.intel.com>
> > Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: intel-gfx at lists.freedesktop.org
> > Cc: <stable at vger.kernel.org> # v3.13+
> >
> > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> > ---
> > drivers/gpu/drm/i915/display/intel_display.c | 34 ++++++++++++++------
> > drivers/gpu/drm/i915/i915_reg.h | 16 ++++++---
> > 2 files changed, 35 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index b25c596f6f7e..a257e5dc381c 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -5838,16 +5838,18 @@ static void bdw_set_pipemisc(const struct
> > intel_crtc_state *crtc_state)
> >
> > switch (crtc_state->pipe_bpp) {
> > case 18:
> > - val |= PIPEMISC_DITHER_6_BPC;
> > + val |= PIPEMISC_6_BPC;
> > break;
> > case 24:
> > - val |= PIPEMISC_DITHER_8_BPC;
> > + val |= PIPEMISC_8_BPC;
> > break;
> > case 30:
> > - val |= PIPEMISC_DITHER_10_BPC;
> > + val |= PIPEMISC_10_BPC;
> > break;
> > case 36:
> > - val |= PIPEMISC_DITHER_12_BPC;
> > + /* Port output 12BPC defined for ADLP+ */
> > + if (DISPLAY_VER(dev_priv) > 12)
> > + val |= PIPEMISC_12_BPC_ADLP;
> > break;
> > default:
> > MISSING_CASE(crtc_state->pipe_bpp);
> > @@ -5900,15 +5902,27 @@ int bdw_get_pipemisc_bpp(struct intel_crtc
> > *crtc)
> >
> > tmp = intel_de_read(dev_priv, PIPEMISC(crtc->pipe));
> >
> > - switch (tmp & PIPEMISC_DITHER_BPC_MASK) {
> > - case PIPEMISC_DITHER_6_BPC:
> > + switch (tmp & PIPEMISC_BPC_MASK) {
> > + case PIPEMISC_6_BPC:
> > return 18;
> > - case PIPEMISC_DITHER_8_BPC:
> > + case PIPEMISC_8_BPC:
> > return 24;
> > - case PIPEMISC_DITHER_10_BPC:
> > + case PIPEMISC_10_BPC:
> > return 30;
> > - case PIPEMISC_DITHER_12_BPC:
> > - return 36;
> > + /*
> > + * PORT OUTPUT 12 BPC defined for ADLP+.
> > + *
> > + * TODO:
> > + * For previous platforms with DSI interface, bits 5:7
> > + * are used for storing pipe_bpp irrespective of dithering.
> > + * Since the value of 12 BPC is not defined for these bits
> > + * on older platforms, need to find a workaround for 12 BPC
> > + * MIPI DSI HW readout.
> > + */
> > + case PIPEMISC_12_BPC_ADLP:
> > + if (DISPLAY_VER(dev_priv) > 12)
> > + return 36;
> > + fallthrough;
> > default:
> > MISSING_CASE(tmp);
> > return 0;
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h index 167eaa87501b..664970f2bc62
> > 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -6203,11 +6203,17 @@ enum {
> > #define PIPEMISC_HDR_MODE_PRECISION (1 << 23) /* icl+ */
> > #define PIPEMISC_OUTPUT_COLORSPACE_YUV (1 << 11)
> > #define PIPEMISC_PIXEL_ROUNDING_TRUNC REG_BIT(8) /* tgl+ */
> > -#define PIPEMISC_DITHER_BPC_MASK (7 << 5)
> > -#define PIPEMISC_DITHER_8_BPC (0 << 5)
> > -#define PIPEMISC_DITHER_10_BPC (1 << 5)
> > -#define PIPEMISC_DITHER_6_BPC (2 << 5)
> > -#define PIPEMISC_DITHER_12_BPC (3 << 5)
> > +/*
> > + * For Display < 13, Bits 5-7 of PIPE MISC represent DITHER BPC with
> > + * valid values of: 6, 8, 10 BPC.
> > + * ADLP+, the bits 5-7 represent PORT OUTPUT BPC with valid values of:
> > + * 6, 8, 10, 12 BPC.
> > + */
> > +#define PIPEMISC_BPC_MASK (7 << 5)
> > +#define PIPEMISC_8_BPC (0 << 5)
> > +#define PIPEMISC_10_BPC (1 << 5)
> > +#define PIPEMISC_6_BPC (2 << 5)
> > +#define PIPEMISC_12_BPC_ADLP (4 << 5) /* adlp+ */
> > #define PIPEMISC_DITHER_ENABLE (1 << 4)
> > #define PIPEMISC_DITHER_TYPE_MASK (3 << 2)
> > #define PIPEMISC_DITHER_TYPE_SP (0 << 2)
> > --
> > 2.25.1
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