[Intel-gfx] [PATCH v3 1/5] drm/i915: Correctly handle limited range YCbCr data on VLV/CHV

Sharma, Shashank shashank.sharma at intel.com
Tue Jun 20 14:43:42 UTC 2017


Regards

Shashank


On 6/20/2017 8:04 PM, Ville Syrjälä wrote:
> On Tue, Jun 20, 2017 at 07:27:54PM +0530, Sharma, Shashank wrote:
>> Regards
>> Shashank
>>
>> On 6/20/2017 7:02 PM, ville.syrjala at linux.intel.com wrote:
>>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>>
>>> Turns out the VLV/CHV fixed function sprite CSC expects full range
>>> data as input. We've been feeding it limited range data to it all
>>> along. To expand the data out to full range we'll use the color
>>> correction registers (brightness, contrast, and saturation).
>>>
>>> On CHV pipe B we were actually doing the right thing already because we
>>> progammed the custom CSC matrix to do expect limited range input. Now
>>> that well pre-expand the data out with the color correction unit, we
>>> need to change the CSC matrix to operate with full range input instead.
>>>
>>> This should make the sprite output of the other pipes match the sprite
>>> output of pipe B reasonably well. Looking at the resulting pipe CRCs,
>>> there can be a slight difference in the output, but as I don't know
>>> the formula used by the fixed function CSC of the other pipes, I don't
>>> think it's worth the effort to try to match the output exactly. It
>>> might not even be possible due to difference in internal precision etc.
>>>
>>> One slight caveat here is that the color correction registers are single
>>> bufferred, so we should really be updating them during vblank, but we
>>> still don't have a mechanism for that, so just toss in another FIXME.
>>>
>>> v2: Rebase
>>> v3: s/bri/brightness/ s/con/contrast/ (Shashank)
>>>
>>> Cc: Shashank Sharma <shashank.sharma at intel.com>
>>> Cc: Jyri Sarha <jsarha at ti.com>
>>> Cc: "Tang, Jun" <jun.tang at intel.com>
>>> Reported-by: "Tang, Jun" <jun.tang at intel.com>
>>> Cc: stable at vger.kernel.org
>>> Fixes: 7f1f3851feb0 ("drm/i915: sprite support for ValleyView v4")
>>> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/i915_reg.h     | 10 +++++
>>>    drivers/gpu/drm/i915/intel_sprite.c | 74 ++++++++++++++++++++++++++++---------
>>>    2 files changed, 66 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>>> index c8647cfa81ba..290322588f56 100644
>>> --- a/drivers/gpu/drm/i915/i915_reg.h
>>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>>> @@ -5974,6 +5974,12 @@ enum {
>>>    #define _SPATILEOFF		(VLV_DISPLAY_BASE + 0x721a4)
>>>    #define _SPACONSTALPHA		(VLV_DISPLAY_BASE + 0x721a8)
>>>    #define   SP_CONST_ALPHA_ENABLE		(1<<31)
>>> +#define _SPACLRC0		(VLV_DISPLAY_BASE + 0x721d0)
>>> +#define   SP_CONTRAST(x)		((x) << 18) /* u3.6 */
>> protection for higher reserved bits ? From 27-31 ? something like ((x &
>> 1FF) << 18) ?
> It's unsigned, so no need.
Humm .. doesn't stops me to pass a bigger value, which will be shifted 
towards reserved bits ?
>
>>> +#define   SP_BRIGHTNESS(x)		((x) & 0xff) /* s8 */
>>> +#define _SPACLRC1		(VLV_DISPLAY_BASE + 0x721d4)
>>> +#define   SP_SH_SIN(x)			(((x) & 0x7ff) << 16) /* s4.7 */
>>> +#define   SP_SH_COS(x)			(x) /* u3.7 */
>>>    
>> #define   SP_SH_COS(x)			(x & 3FF) /* u3.7 */ ?
> Also unsigned
>
>>> #define _SPAGAMC		(VLV_DISPLAY_BASE + 0x721f4)
>>>    
>>>    #define _SPBCNTR		(VLV_DISPLAY_BASE + 0x72280)
>>> @@ -5987,6 +5993,8 @@ enum {
>>>    #define _SPBKEYMAXVAL		(VLV_DISPLAY_BASE + 0x722a0)
>>>    #define _SPBTILEOFF		(VLV_DISPLAY_BASE + 0x722a4)
>>>    #define _SPBCONSTALPHA		(VLV_DISPLAY_BASE + 0x722a8)
>>> +#define _SPBCLRC0		(VLV_DISPLAY_BASE + 0x722d0)
>>> +#define _SPBCLRC1		(VLV_DISPLAY_BASE + 0x722d4)
>>>    #define _SPBGAMC		(VLV_DISPLAY_BASE + 0x722f4)
>>>    
>>>    #define _MMIO_VLV_SPR(pipe, plane_id, reg_a, reg_b) \
>>> @@ -6003,6 +6011,8 @@ enum {
>>>    #define SPKEYMAXVAL(pipe, plane_id)	_MMIO_VLV_SPR((pipe), (plane_id), _SPAKEYMAXVAL, _SPBKEYMAXVAL)
>>>    #define SPTILEOFF(pipe, plane_id)	_MMIO_VLV_SPR((pipe), (plane_id), _SPATILEOFF, _SPBTILEOFF)
>>>    #define SPCONSTALPHA(pipe, plane_id)	_MMIO_VLV_SPR((pipe), (plane_id), _SPACONSTALPHA, _SPBCONSTALPHA)
>>> +#define SPCLRC0(pipe, plane_id)		_MMIO_VLV_SPR((pipe), (plane_id), _SPACLRC0, _SPBCLRC0)
>>> +#define SPCLRC1(pipe, plane_id)		_MMIO_VLV_SPR((pipe), (plane_id), _SPACLRC1, _SPBCLRC1)
>>>    #define SPGAMC(pipe, plane_id)		_MMIO_VLV_SPR((pipe), (plane_id), _SPAGAMC, _SPBGAMC)
>>>    
>>>    /*
>>> diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
>>> index 0c650c2cbca8..4462408cc835 100644
>>> --- a/drivers/gpu/drm/i915/intel_sprite.c
>>> +++ b/drivers/gpu/drm/i915/intel_sprite.c
>>> @@ -325,44 +325,80 @@ skl_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
>>>    }
>>>    
>>>    static void
>>> -chv_update_csc(struct intel_plane *plane, uint32_t format)
>>> +chv_update_csc(const struct intel_plane_state *plane_state)
>>>    {
>>> +	struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
>>>    	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
>>> +	const struct drm_framebuffer *fb = plane_state->base.fb;
>>>    	enum plane_id plane_id = plane->id;
>>>    
>>>    	/* Seems RGB data bypasses the CSC always */
>>> -	if (!format_is_yuv(format))
>>> +	if (!format_is_yuv(fb->format->format))
>>>    		return;
>>>    
>>>    	/*
>>> -	 * BT.601 limited range YCbCr -> full range RGB
>>> +	 * BT.601 full range YCbCr -> full range RGB
>>>    	 *
>>> -	 * |r|   | 6537 4769     0|   |cr  |
>>> -	 * |g| = |-3330 4769 -1605| x |y-64|
>>> -	 * |b|   |    0 4769  8263|   |cb  |
>>> +	 * |r|   | 5743 4096     0|   |cr|
>>> +	 * |g| = |-2925 4096 -1410| x |y |
>>> +	 * |b|   |    0 4096  7258|   |cb|
>>>    	 *
>>> -	 * Cb and Cr apparently come in as signed already, so no
>>> -	 * need for any offset. For Y we need to remove the offset.
>>> +	 * Cb and Cr apparently come in as signed already,
>>> +	 * and we get full range data in on account of CLRC0/1
>>>    	 */
>>> -	I915_WRITE_FW(SPCSCYGOFF(plane_id), SPCSC_OOFF(0) | SPCSC_IOFF(-64));
>>> +	I915_WRITE_FW(SPCSCYGOFF(plane_id), SPCSC_OOFF(0) | SPCSC_IOFF(0));
>>>    	I915_WRITE_FW(SPCSCCBOFF(plane_id), SPCSC_OOFF(0) | SPCSC_IOFF(0));
>>>    	I915_WRITE_FW(SPCSCCROFF(plane_id), SPCSC_OOFF(0) | SPCSC_IOFF(0));
>>>    
>>> -	I915_WRITE_FW(SPCSCC01(plane_id), SPCSC_C1(4769) | SPCSC_C0(6537));
>>> -	I915_WRITE_FW(SPCSCC23(plane_id), SPCSC_C1(-3330) | SPCSC_C0(0));
>>> -	I915_WRITE_FW(SPCSCC45(plane_id), SPCSC_C1(-1605) | SPCSC_C0(4769));
>>> -	I915_WRITE_FW(SPCSCC67(plane_id), SPCSC_C1(4769) | SPCSC_C0(0));
>>> -	I915_WRITE_FW(SPCSCC8(plane_id), SPCSC_C0(8263));
>>> +	I915_WRITE_FW(SPCSCC01(plane_id), SPCSC_C1(4096) | SPCSC_C0(5743));
>>> +	I915_WRITE_FW(SPCSCC23(plane_id), SPCSC_C1(-2925) | SPCSC_C0(0));
>>> +	I915_WRITE_FW(SPCSCC45(plane_id), SPCSC_C1(-1410) | SPCSC_C0(4096));
>>> +	I915_WRITE_FW(SPCSCC67(plane_id), SPCSC_C1(4096) | SPCSC_C0(0));
>>> +	I915_WRITE_FW(SPCSCC8(plane_id), SPCSC_C0(7258));
>>>    
>>> -	I915_WRITE_FW(SPCSCYGICLAMP(plane_id), SPCSC_IMAX(940) | SPCSC_IMIN(64));
>>> -	I915_WRITE_FW(SPCSCCBICLAMP(plane_id), SPCSC_IMAX(448) | SPCSC_IMIN(-448));
>>> -	I915_WRITE_FW(SPCSCCRICLAMP(plane_id), SPCSC_IMAX(448) | SPCSC_IMIN(-448));
>>> +	I915_WRITE_FW(SPCSCYGICLAMP(plane_id), SPCSC_IMAX(1023) | SPCSC_IMIN(0));
>>> +	I915_WRITE_FW(SPCSCCBICLAMP(plane_id), SPCSC_IMAX(512) | SPCSC_IMIN(-512));
>>> +	I915_WRITE_FW(SPCSCCRICLAMP(plane_id), SPCSC_IMAX(512) | SPCSC_IMIN(-512));
>>>    
>>>    	I915_WRITE_FW(SPCSCYGOCLAMP(plane_id), SPCSC_OMAX(1023) | SPCSC_OMIN(0));
>>>    	I915_WRITE_FW(SPCSCCBOCLAMP(plane_id), SPCSC_OMAX(1023) | SPCSC_OMIN(0));
>>>    	I915_WRITE_FW(SPCSCCROCLAMP(plane_id), SPCSC_OMAX(1023) | SPCSC_OMIN(0));
>>>    }
>>>    
>>> +static void
>>> +vlv_update_clrc(const struct intel_plane_state *plane_state)
>>> +{
>>> +	struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
>>> +	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
>>> +	const struct drm_framebuffer *fb = plane_state->base.fb;
>>> +	enum pipe pipe = plane->pipe;
>>> +	enum plane_id plane_id = plane->id;
>>> +	int contrast, brightness, sh_sin, sh_cos;
>>> +
>>> +	if (format_is_yuv(fb->format->format)) {
>>> +		/*
>>> +		 * expand limited range to full range.
>>> +		 * contrast is applied first, then brightness
>>> +		 */
>> I would be happy to see some comment explaining the Brightness/Contrast
>> calculation magic nos, or may be a hint for other developers.
> Y: 16-235 * contrast + brightness -> ~0->255
> CbCr: no hue adjustemnt -> 0 degree angle
>        scale to expand CbCr range from -112-112 to -128-128
>        sh_sin = sin(0) * 128/112 = 0
>        sh_cos = cos(0) * 128/112 = whatever
Yep, (fortunately I am aware of this formula :-)), this same in form of 
a comment ?
With of without this comment, feel free to use:
R-B: Shashank Sharma <shashank.sharma at intel.com>
>>> +		contrast = ((255 << 7) / 219 + 1) >> 1;
>>> +		brightness = -((16 << 1) * 255 / 219 + 1) >> 1;
>>> +		sh_sin = 0;
>>> +		sh_cos = (((128 << 8) / 112) + 1) >> 1;
>>> +	} else {
>>> +		/* pass-through everything */
>>> +		contrast = 1 << 6;
>>> +		brightness = 0;
>>> +		sh_sin = 0;
>>> +		sh_cos = 1 << 7;
>>> +	}
>>> +
>>> +	/* FIXME these register are single buffered :( */
>>> +	I915_WRITE_FW(SPCLRC0(pipe, plane_id),
>>> +		      SP_CONTRAST(contrast) | SP_BRIGHTNESS(brightness));
>>> +	I915_WRITE_FW(SPCLRC1(pipe, plane_id),
>>> +		      SP_SH_SIN(sh_sin) | SP_SH_COS(sh_cos));
>>> +}
>>> +
>>>    static u32 vlv_sprite_ctl(const struct intel_crtc_state *crtc_state,
>>>    			  const struct intel_plane_state *plane_state)
>>>    {
>>> @@ -456,8 +492,10 @@ vlv_update_plane(struct intel_plane *plane,
>>>    
>>>    	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
>>>    
>>> +	vlv_update_clrc(plane_state);
>>> +
>>>    	if (IS_CHERRYVIEW(dev_priv) && pipe == PIPE_B)
>>> -		chv_update_csc(plane, fb->format->format);
>>> +		chv_update_csc(plane_state);
>>>    
>>>    	if (key->flags) {
>>>    		I915_WRITE_FW(SPKEYMINVAL(pipe, plane_id), key->min_value);



More information about the Intel-gfx mailing list