++ Ankit
> >
> > On Tue, 08 Aug 2023, Suraj Kandpal <suraj.kandpal@xxxxxxxxx> wrote:
> > > Add function to read any PPS register based on the intel_dsc_pps
> > > enum provided. Add a function which will call the new pps read
> > > function and place it in crtc state. Only PPS0 and
> > > PPS1 are readout the rest of the registers will be read in upcoming
> > > patches.
> > >
> > > --v2
> > > -Changes in read function as PPS enum is removed -Initialize pps_val
> > > as 0 in pps_read func itself [Jani] -Create a function that gets the
> > > required register and call that in the common read function [Jani]
> > > -Move the drm_WARN_ON one abstraction layer above [Jani]
> > >
> > > --v3
> > > -Send both reg values regardless of dsc engine no [Jani] -Don't use
> > > num_vdsc_instances stick to dsc_split field [Ankit]
> > >
> > > --v4
> > > -Manipulate the reg values instead of creating MACRO to change name
> > > of pps [Ankit]
> > >
> > > --v5
> > > -Read dsc reg values using array rather than individual variables
> > > [Ankit] -Loop the verification of all dsc engine reads to future
> > > proof it [Ankit] -Keep the fix me comment in this patch and remove
> > > it in later one where we add other readouts [Ankit] -Add switch
> > > statement that fills in the required registers based on no of vdsc
> > > engines per pipe.
> > >
> > > --v7
> > > -Pass no of vdsc instances from read_reg function [Ankit] -Fix issue
> > > where arrays do not get freed on return for read_and_verify func
> > > [Ankit]
> > >
> > > Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_vdsc.c | 129 +++++++++++++-----
> > > .../gpu/drm/i915/display/intel_vdsc_regs.h | 12 ++
> > > 2 files changed, 105 insertions(+), 36 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c
> > > b/drivers/gpu/drm/i915/display/intel_vdsc.c
> > > index dc86514d9e17..aa93228ca7af 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> > > @@ -365,6 +365,28 @@ int intel_dsc_get_num_vdsc_instances(const
> > struct intel_crtc_state *crtc_state)
> > > return num_vdsc_instances;
> > > }
> > >
> > > +static void intel_dsc_get_pps_reg(const struct intel_crtc_state
> > *crtc_state, int pps,
> > > + i915_reg_t *dsc_reg, int no_vdsc_per_pipe)
> > {
> > > + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > > + enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> > > + enum pipe pipe = crtc->pipe;
> > > + bool pipe_dsc;
> >
> > Matter of taste, but to me that's four local variables too many for
> > small things like this.
> >
> > > +
> > > + pipe_dsc = is_pipe_dsc(crtc, cpu_transcoder);
> > > +
> > > + switch (no_vdsc_per_pipe) {
> > > + case 2:
> > > + dsc_reg[1] = pipe_dsc ? ICL_DSC1_PPS_REG(pipe, pps) :
> > DSCC_PPS_REG(pps);
> > > + fallthrough;
> > > + case 1:
> > > + dsc_reg[0] = pipe_dsc ? ICL_DSC0_PPS_REG(pipe, pps) :
> > DSCA_PPS_REG(pps);
> > > + break;
> > > + default:
> > > + MISSING_CASE(no_vdsc_per_pipe);
> > > + }
> > > +}
> > > +
> > > static void intel_dsc_pps_configure(const struct intel_crtc_state
> > > *crtc_state) {
> > > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > > @@ -994,17 +1016,83 @@ void intel_dsc_disable(const struct
> > intel_crtc_state *old_crtc_state)
> > > }
> > > }
> > >
> > > +static int intel_dsc_read_pps_reg(struct intel_crtc_state *crtc_state,
> > > + int pps, u32 *pps_val)
> > > +{
> > > + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > > + struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> > > + const int no_vdsc_per_pipe =
> > intel_dsc_get_vdsc_per_pipe(crtc_state);
> > > + i915_reg_t *dsc_reg;
> > > + u32 *pps_temp;
> > > + int i, ret = 0;
> > > +
> > > + dsc_reg = kcalloc(no_vdsc_per_pipe, sizeof(dsc_reg), GFP_KERNEL);
> > > + if (!dsc_reg)
> > > + return -ENOMEM;
> > > +
> > > + pps_temp = kcalloc(no_vdsc_per_pipe, sizeof(pps_temp),
> > GFP_KERNEL);
> > > + if (!pps_temp) {
> > > + kfree(dsc_reg);
> > > + return -ENOMEM;
> > > + }
> >
> > no_vdsc_per_pipe is at most 2. Temporary dynamic allocation is way
> > overkill here.
>
> Yes but Ankit was of the thought that we can future proof this going forward
> if by any chance we get more dsc engines
>
> >
> > > +
> > > + *pps_val = 0;
> > > + intel_dsc_get_pps_reg(crtc_state, pps, dsc_reg, no_vdsc_per_pipe);
> > > + *pps_val = intel_de_read(i915, dsc_reg[0]);
> > > + if (no_vdsc_per_pipe > 1) {
> > > + for (i = 0; i < no_vdsc_per_pipe - 1; i++) {
> > > + pps_temp[i] = intel_de_read(i915, dsc_reg[i]);
> > > + pps_temp[i + 1] = intel_de_read(i915, dsc_reg[i + 1]);
> > > + if (pps_temp[i] != pps_temp[i + 1]) {
> > > + ret = 1;
> > > + break;
> > > + }
> > > + }
> > > + }
> >
> > What is going on here? Feels like this has grown way more complicated
> > than it needs to be since I last looked at this series. :(
>
> In case of more than 2 vdsc engines (just for future proofing) this loops looks
> at all the registers being used for that pipe and makes sure everyone has the
> same value
>
> Regards,
> Suraj Kandpal
> >
> > > +
> > > + kfree(dsc_reg);
> > > + kfree(pps_temp);
> > > + return ret;
> > > +}
> > > +
> > > +static void intel_dsc_read_and_verify_pps_reg(struct
> > > +intel_crtc_state
> > *crtc_state,
> > > + int pps, u32 *pps_val)
> > > +{
> > > + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > > + struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> > > + int ret;
> > > +
> > > + ret = intel_dsc_read_pps_reg(crtc_state, pps, pps_val);
> > > + drm_WARN_ON(&i915->drm, ret);
> > > +}
> > > +
> > > +static void intel_dsc_get_pps_config(struct intel_crtc_state
> > > +*crtc_state) {
> > > + struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config;
> > > + u32 pps_temp1, pps_temp2;
> > > +
> > > + /* FIXME: add more state readout as needed */
> > > +
> > > + /* Readout PPS_0 and PPS_1 registers */
> > > + intel_dsc_read_and_verify_pps_reg(crtc_state, 0, &pps_temp1);
> > > + intel_dsc_read_and_verify_pps_reg(crtc_state, 1, &pps_temp2);
> > > +
> > > + vdsc_cfg->bits_per_pixel = pps_temp2;
> > > +
> > > + if (pps_temp1 & DSC_NATIVE_420_ENABLE)
> > > + vdsc_cfg->bits_per_pixel >>= 1;
> > > +
> > > + crtc_state->dsc.compressed_bpp = vdsc_cfg->bits_per_pixel >> 4; }
> > > +
> > > void intel_dsc_get_config(struct intel_crtc_state *crtc_state) {
> > > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > > struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> > > - struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config;
> > > enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> > > - enum pipe pipe = crtc->pipe;
> > > enum intel_display_power_domain power_domain;
> > > intel_wakeref_t wakeref;
> > > - u32 dss_ctl1, dss_ctl2, pps0 = 0, pps1 = 0, pps_temp0, pps_temp1;
> > > - int no_vdsc_instances_per_pipe;
> > > + u32 dss_ctl1, dss_ctl2;
> > >
> > > if (!intel_dsc_source_support(crtc_state))
> > > return;
> > > @@ -1025,38 +1113,7 @@ void intel_dsc_get_config(struct
> > > intel_crtc_state
> > *crtc_state)
> > > crtc_state->dsc.dsc_split = (dss_ctl2 &
> > RIGHT_BRANCH_VDSC_ENABLE) &&
> > > (dss_ctl1 & JOINER_ENABLE);
> > >
> > > - /* FIXME: add more state readout as needed */
> > > -
> > > - no_vdsc_instances_per_pipe =
> > intel_dsc_get_vdsc_per_pipe(crtc_state);
> > > -
> > > - /* PPS0 & PPS1 */
> > > - if (!is_pipe_dsc(crtc, cpu_transcoder)) {
> > > - pps1 = intel_de_read(dev_priv,
> > DSCA_PICTURE_PARAMETER_SET_1);
> > > - if (no_vdsc_instances_per_pipe > 1) {
> > > - pps_temp1 = intel_de_read(dev_priv,
> > DSCC_PICTURE_PARAMETER_SET_1);
> > > - drm_WARN_ON(&dev_priv->drm, pps1 !=
> > pps_temp1);
> > > - }
> > > - } else {
> > > - pps0 = intel_de_read(dev_priv,
> > > -
> > ICL_DSC0_PICTURE_PARAMETER_SET_0(pipe));
> > > - pps1 = intel_de_read(dev_priv,
> > > -
> > ICL_DSC0_PICTURE_PARAMETER_SET_1(pipe));
> > > - if (no_vdsc_instances_per_pipe > 1) {
> > > - pps_temp0 = intel_de_read(dev_priv,
> > > -
> > ICL_DSC1_PICTURE_PARAMETER_SET_0(pipe));
> > > - pps_temp1 = intel_de_read(dev_priv,
> > > -
> > ICL_DSC1_PICTURE_PARAMETER_SET_1(pipe));
> > > - drm_WARN_ON(&dev_priv->drm, pps0 !=
> > pps_temp0);
> > > - drm_WARN_ON(&dev_priv->drm, pps1 !=
> > pps_temp1);
> > > - }
> > > - }
> > > -
> > > - vdsc_cfg->bits_per_pixel = pps1;
> > > -
> > > - if (pps0 & DSC_NATIVE_420_ENABLE)
> > > - vdsc_cfg->bits_per_pixel >>= 1;
> > > -
> > > - crtc_state->dsc.compressed_bpp = vdsc_cfg->bits_per_pixel >> 4;
> > > + intel_dsc_get_pps_config(crtc_state);
> > > out:
> > > intel_display_power_put(dev_priv, power_domain, wakeref); } diff
> > > --git a/drivers/gpu/drm/i915/display/intel_vdsc_regs.h
> > > b/drivers/gpu/drm/i915/display/intel_vdsc_regs.h
> > > index 785ede31116e..862dc708c5fc 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_vdsc_regs.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_vdsc_regs.h
> > > @@ -78,6 +78,10 @@
> > > /* Icelake Display Stream Compression Registers */
> > > #define DSCA_PICTURE_PARAMETER_SET_0
> _MMIO(0x6B200)
> > > #define DSCC_PICTURE_PARAMETER_SET_0
> _MMIO(0x6BA00)
> > > +#define DSCA_PPS_0 0x6B200
> > > +#define DSCC_PPS_0 0x6BA00
> > > +#define DSCA_PPS_REG(pps) _MMIO(DSCA_PPS_0
> > + (pps) * 4)
> > > +#define DSCC_PPS_REG(pps) _MMIO(DSCC_PPS_0
> > + (pps) * 4)
> > > #define _ICL_DSC0_PICTURE_PARAMETER_SET_0_PB 0x78270
> > > #define _ICL_DSC1_PICTURE_PARAMETER_SET_0_PB 0x78370
> > > #define _ICL_DSC0_PICTURE_PARAMETER_SET_0_PC 0x78470
> > > @@ -88,6 +92,14 @@
> > > #define ICL_DSC1_PICTURE_PARAMETER_SET_0(pipe)
> > _MMIO_PIPE((pipe) - PIPE_B, \
> > >
> > _ICL_DSC1_PICTURE_PARAMETER_SET_0_PB, \
> > >
> > _ICL_DSC1_PICTURE_PARAMETER_SET_0_PC)
> > > +#define ICL_DSC0_PPS_0(pipe) _PICK_EVEN((pipe) -
> > PIPE_B, \
> > > +
> > _ICL_DSC0_PICTURE_PARAMETER_SET_0_PB, \
> > > +
> > _ICL_DSC0_PICTURE_PARAMETER_SET_0_PC)
> > > +#define ICL_DSC1_PPS_0(pipe) _PICK_EVEN((pipe) -
> > PIPE_B, \
> > > +
> > _ICL_DSC1_PICTURE_PARAMETER_SET_0_PB, \
> > > +
> > _ICL_DSC1_PICTURE_PARAMETER_SET_0_PC)
> > > +#define ICL_DSC0_PPS_REG(pipe, pps)
> > _MMIO(ICL_DSC0_PPS_0(pipe) + ((pps) * 4))
> > > +#define ICL_DSC1_PPS_REG(pipe, pps)
> > _MMIO(ICL_DSC1_PPS_0(pipe) + ((pps) * 4))
> > > #define DSC_NATIVE_422_ENABLE BIT(23)
> > > #define DSC_NATIVE_420_ENABLE BIT(22)
> > > #define DSC_ALT_ICH_SEL (1 << 20)
> >
> > --
> > Jani Nikula, Intel Open Source Graphics Center
