Re: [PATCH 3/4] [v5] drm/i915/color: Extract icl_read_luts()

Ville Syrjälä
2019-10-15T12:34:33Z

On Thu, Oct 10, 2019 at 04:20:04PM +0530, Sharma, Swati2 wrote:
> On 09-Oct-19 7:46 PM, Ville Syrjälä wrote:
> > On Wed, Oct 09, 2019 at 12:25:41PM +0530, Swati Sharma wrote:
> >> For icl+, have hw read out to create hw blob of gamma
> >> lut values. icl+ platforms supports multi segmented gamma
> >> mode by default, add hw lut creation for this mode.
> >>
> >> This will be used to validate gamma programming using dsb
> >> (display state buffer) which is a tgl specific feature.
> >>
> >> Major change done-removal of readouts of coarse and fine segments
> >> because PAL_PREC_DATA register isn't giving propoer values.
> >> State checker limited only to "fine segment"
> >>
> >> v2: -readout code for multisegmented gamma has to come
> >> up with some intermediate entries that aren't preserved
> >> in hardware (Jani N)
> >> -linear interpolation (Ville)
> >> -moved common code to check gamma_enable to specific funcs,
> >> since icl doesn't support that
> >> v3: -use u16 instead of __u16 [Jani N]
> >> -used single lut [Jani N]
> >> -improved and more readable for loops [Jani N]
> >> -read values directly to actual locations and then fill gaps [Jani N]
> >> -moved cleaning to patch 1 [Jani N]
> >> -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
> >> make it similar to icl_load_luts()
> >> -renamed icl_compute_interpolated_gamma_blob() to
> >> icl_compute_interpolated_gamma_lut_values() more sensible, I guess
> >> v4: -removed interpolated func for creating gamma lut values
> >> -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
> >> correctly
> >> v5: -added gamma_enable check inside read_luts()
> >>
> >> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> >> ---
> >> drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
> >> drivers/gpu/drm/i915/i915_reg.h | 6 ++
> >> 2 files changed, 108 insertions(+), 12 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> >> index fa44eb73d088..614e0ad386ca 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_color.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> >> @@ -1477,6 +1477,25 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
> >> }
> >> }
> >>
> >> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
> >> +{
> >> + if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
> >> + return 0;
> >> +
> >> + switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
> >> + case GAMMA_MODE_MODE_8BIT:
> >> + return 8;
> >> + case GAMMA_MODE_MODE_10BIT:
> >> + return 10;
> >> + case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> >> + return 16;
> >> + default:
> >> + MISSING_CASE(crtc_state->gamma_mode);
> >> + return 0;
> >> + }
> >> +
> >> +}
> >> +
> >> int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
> >> {
> >> struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> >> @@ -1488,7 +1507,9 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
> >> else
> >> return i9xx_gamma_precision(crtc_state);
> >> } else {
> >> - if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> >> + if (INTEL_GEN(dev_priv) >= 11)
> >> + return icl_gamma_precision(crtc_state);
> >> + else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> >> return glk_gamma_precision(crtc_state);
> >> else if (IS_IRONLAKE(dev_priv))
> >> return ilk_gamma_precision(crtc_state);
> >> @@ -1519,6 +1540,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
> >> return true;
> >> }
> >>
> >> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> >> + struct drm_color_lut *lut2,
> >> + int lut_size, u32 err)
> >> +{
> >> + int i;
> >> +
> >> + for (i = 0; i < 9; i++) {
> >> + if (!err_check(&lut1[i], &lut2[i], err))
> >> + return false;
> >> + }
> >> +
> >> + return true;
> >> +}
> >> +
> >> bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >> struct drm_property_blob *blob2,
> >> u32 gamma_mode, u32 bit_precision)
> >> @@ -1537,16 +1572,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >> lut_size2 = drm_color_lut_size(blob2);
> >>
> >> /* check sw and hw lut size */
> >> - switch (gamma_mode) {
> >> - case GAMMA_MODE_MODE_8BIT:
> >> - case GAMMA_MODE_MODE_10BIT:
> >> - if (lut_size1 != lut_size2)
> >> - return false;
> >> - break;
> >> - default:
> >> - MISSING_CASE(gamma_mode);
> >> - return false;
> >> - }
> >> + if (lut_size1 != lut_size2)
> >> + return false;
> >>
> >> lut1 = blob1->data;
> >> lut2 = blob2->data;
> >> @@ -1554,13 +1581,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >> err = 0xffff >> bit_precision;
> >>
> >> /* check sw and hw lut entry to be equal */
> >> - switch (gamma_mode) {
> >> + switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
> >> case GAMMA_MODE_MODE_8BIT:
> >> case GAMMA_MODE_MODE_10BIT:
> >> if (!intel_color_lut_entry_equal(lut1, lut2,
> >> lut_size2, err))
> >> return false;
> >> break;
> >> + case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> >> + if (!intel_color_lut_entry_multi_equal(lut1, lut2,
> >> + lut_size2, err))
> >
> > I don't think you need a new function for that. Just pass 9 as the size
> > to intel_color_lut_entry_equal() ?
>
> I had made a separate function for multi-segmented gamma since there
> will be 3 loops for comparing superfine, fine and course segments which
> wont go with intel_lut_entry_equal() structure.
>
> Right now we are limiting to superfine segment only but in future we
> will add for other segments too (once we get fix from h/w)
>
> Func() should look like this. Actually there is no need to passing
> lut_size only in this function if we continue with this function only.
>
> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> + struct drm_color_lut *lut2,
> + int lut_size, u32 err)
> +{
> + int i;
> +
> + for (i = 0; i < 9; i++) {
> + if (!err_check(&lut1[i], &lut2[i], err))
> + return false;
> + }
> +
> + for (i = 1; i < 257; i++) {
> + if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
> + return false;
> + }
> +
> + for (i = 0; i < 256; i++) {
> + if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
> + return false;
> + }
> +
> + return true;
> +}
> +
> Please suggest.

There's not much point in duplicating code until it's proven to
be required. Who knows when the hw gets fixed, maybe never.

>
> >
> > Hmm, should probably rename that to just intel_color_lut_equal() since
> > it checks the entire LUT (or at least the specified subset) and not
> > just a single entry...
>
> This will be fine for this segment but for other two segments it won't
> work. Right?

We could generalize it to take start+end+stride. Dunno if that would be
particularly beneficial though.

--
Ville Syrjälä
Intel