drm/dp_mst: Add PBN calculation for DSC modes

With DSC, bpp can be fractional in multiples of 1/16.

Change drm_dp_calc_pbn_mode to reflect this, adding a new
parameter bool dsc. When this parameter is true, treat the
bpp parameter as having units not of bits per pixel, but
1/16 of a bit per pixel

v2: Don't add separate function for this
v3: In the equation divide bpp by 16 as it is expected
not to leave any remainder
v4: Added DSC test parameters for selftest

Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: David Francis <David.Francis@amd.com>
Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
David Francis 2019-08-21 10:33:26 -04:00 committed by Alex Deucher
parent 0f899fd466
commit dc48529fb1
7 changed files with 25 additions and 11 deletions

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@ -4933,7 +4933,7 @@ static int dm_encoder_helper_atomic_check(struct drm_encoder *encoder,
is_y420);
bpp = convert_dc_color_depth_into_bpc(color_depth) * 3;
clock = adjusted_mode->clock;
dm_new_connector_state->pbn = drm_dp_calc_pbn_mode(clock, bpp);
dm_new_connector_state->pbn = drm_dp_calc_pbn_mode(clock, bpp, false);
}
dm_new_connector_state->vcpi_slots = drm_dp_atomic_find_vcpi_slots(state,
mst_mgr,

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@ -4415,10 +4415,11 @@ EXPORT_SYMBOL(drm_dp_check_act_status);
* drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
* @clock: dot clock for the mode
* @bpp: bpp for the mode.
* @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
*
* This uses the formula in the spec to calculate the PBN value for a mode.
*/
int drm_dp_calc_pbn_mode(int clock, int bpp)
int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
{
/*
* margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
@ -4429,7 +4430,16 @@ int drm_dp_calc_pbn_mode(int clock, int bpp)
* peak_kbps *= (1006/1000)
* peak_kbps *= (64/54)
* peak_kbps *= 8 convert to bytes
*
* If the bpp is in units of 1/16, further divide by 16. Put this
* factor in the numerator rather than the denominator to avoid
* integer overflow
*/
if (dsc)
return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
8 * 54 * 1000 * 1000);
return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
8 * 54 * 1000 * 1000);
}

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@ -61,7 +61,8 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
crtc_state->pipe_bpp = bpp;
crtc_state->pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock,
crtc_state->pipe_bpp);
crtc_state->pipe_bpp,
false);
slots = drm_dp_atomic_find_vcpi_slots(state, &intel_dp->mst_mgr,
port, crtc_state->pbn);

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@ -806,7 +806,7 @@ nv50_msto_atomic_check(struct drm_encoder *encoder,
* topology
*/
asyh->or.bpc = min(connector->display_info.bpc, 8U);
asyh->dp.pbn = drm_dp_calc_pbn_mode(clock, asyh->or.bpc * 3);
asyh->dp.pbn = drm_dp_calc_pbn_mode(clock, asyh->or.bpc * 3, false);
}
slots = drm_dp_atomic_find_vcpi_slots(state, &mstm->mgr, mstc->port,

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@ -518,7 +518,7 @@ static bool radeon_mst_mode_fixup(struct drm_encoder *encoder,
mst_enc = radeon_encoder->enc_priv;
mst_enc->pbn = drm_dp_calc_pbn_mode(adjusted_mode->clock, bpp);
mst_enc->pbn = drm_dp_calc_pbn_mode(adjusted_mode->clock, bpp, false);
mst_enc->primary->active_device = mst_enc->primary->devices & mst_enc->connector->devices;
DRM_DEBUG_KMS("setting active device to %08x from %08x %08x for encoder %d\n",

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@ -18,15 +18,19 @@ int igt_dp_mst_calc_pbn_mode(void *ignored)
int rate;
int bpp;
int expected;
bool dsc;
} test_params[] = {
{ 154000, 30, 689 },
{ 234000, 30, 1047 },
{ 297000, 24, 1063 },
{ 154000, 30, 689, false },
{ 234000, 30, 1047, false },
{ 297000, 24, 1063, false },
{ 332880, 24, 50, true },
{ 324540, 24, 49, true },
};
for (i = 0; i < ARRAY_SIZE(test_params); i++) {
pbn = drm_dp_calc_pbn_mode(test_params[i].rate,
test_params[i].bpp);
test_params[i].bpp,
test_params[i].dsc);
FAIL(pbn != test_params[i].expected,
"Expected PBN %d for clock %d bpp %d, got %d\n",
test_params[i].expected, test_params[i].rate,

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@ -727,8 +727,7 @@ bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
int drm_dp_calc_pbn_mode(int clock, int bpp);
int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc);
bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, int pbn, int slots);