[Intel-gfx] [PATCH v6 4/8] drm/i915/vdsc: Add function to read any PPS register

Nautiyal, Ankit K ankit.k.nautiyal at intel.com
Tue Aug 8 07:48:21 UTC 2023


On 8/7/2023 7:33 PM, Kandpal, Suraj wrote:
>>
>> On 8/3/2023 6:33 PM, Suraj Kandpal 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.
>>>
>>> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/display/intel_vdsc.c     | 128 +++++++++++++-----
>>>    .../gpu/drm/i915/display/intel_vdsc_regs.h    |  12 ++
>>>    2 files changed, 104 insertions(+), 36 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c
>>> b/drivers/gpu/drm/i915/display/intel_vdsc.c
>>> index cd7b7b00be44..f283580c2860 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
>>> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
>>> @@ -365,6 +365,29 @@ 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(struct intel_crtc_state *crtc_state, int
>> pps,
>>> +				  i915_reg_t *dsc_reg)
>>> +{
>>> +	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;
>>> +	int no_vdsc_ins_per_pipe =
>>> +intel_dsc_get_no_vdsc_inst_per_pipe(crtc_state);
>> lets pass dsc_reg count explicitly along with the address of the dsc_reg.
>>
>> Though we are setting the count as per vdsc instances per pipe, but here
>> what we are concerned with filling the dsc_regs
>>
>> and for that semantics, passing dsc_reg count makes more sense to me.
>>
>>> +
>>> +	pipe_dsc = is_pipe_dsc(crtc, cpu_transcoder);
>>> +
>>> +	switch (no_vdsc_ins_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_ins_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 +1017,81 @@ 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_instances_per_pipe =
>> intel_dsc_get_no_vdsc_inst_per_pipe(crtc_state);
>>> +	i915_reg_t *dsc_reg;
>>> +	u32 *pps_temp;
>>> +	int i;
>>> +
>>> +	dsc_reg = kcalloc(no_vdsc_instances_per_pipe, sizeof(dsc_reg),
>> GFP_KERNEL);
>>> +	if (!dsc_reg)
>>> +		return -ENOMEM;
>>> +
>>> +	pps_temp = kcalloc(no_vdsc_instances_per_pipe, sizeof(pps_temp),
>> GFP_KERNEL);
>>> +	if (!pps_temp) {
>>> +		kfree(dsc_reg);
>>> +		return -ENOMEM;
>>> +	}
>>> +
>>> +	*pps_val = 0;
>>> +	intel_dsc_get_pps_reg(crtc_state, pps, dsc_reg);
>>> +	*pps_val = intel_de_read(i915, dsc_reg[0]);
>>> +	if (no_vdsc_instances_per_pipe > 1) {
>>> +		for (i = 0; i < no_vdsc_instances_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])
>>> +				return 1;
>> This will miss to free dsc_reg, pps_temp.
>>
> True will fix that
>
>>> +		}
>>> +	}
>>> +
>>> +	kfree(dsc_reg);
>>> +	kfree(pps_temp);
>>> +	return 0;
>>> +}
>>> +
>>> +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);
>> I think lets pass the num of vdsc instances per pipe from here and propagate
>> to intel_dsc_read_pps_reg.
> Wouldn’t it make more sense to have num of vdsc instances in intel_dsc_read_pps_reg
> and then propagate it to intel_dsc_get_pps_reg  this would increase the argument of only
> intel_dsc_get_pps_reg as opposed to giving an extra argument to intel_dsc_get_pps_reg,
> intel_dsc_read_pps_reg and intel_dsc_read_and_verify_pps_reg.
> Also above you said " Though we are setting the count as per vdsc instances per pipe, but here
> what we are concerned with filling the dsc_regs and for that semantics, passing dsc_reg count
> makes more sense to me."
> And since the dsc registers are getting created inside intel_dsc_reg_read it make more sense to propagate
> Num of vdsc instances from there

Hmm, alright, it does get used intel_dsc_reg_read, we already have 
crtc_state there, so lets compute it there.

Regards,

Ankit

> Regards,
> Suraj Kandpal
>
>> Similar thing to be done in write case in next patch, where dsc_configure_pps
>> computes vdsc instances per pipe and it propagates to
>> intel_dsc_write_pps_reg.
>>
>> Both of which then create a dsc_reg array and call intel_dsc_get_pps_reg.
>>
>>
>> Regards,
>>
>> Ankit
>>
>>> +
>>> +	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 +1112,7 @@ 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_no_vdsc_inst_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)


More information about the Intel-gfx mailing list