Re: [PATCH v4 01/30] drm/docs: Remove unused TV Standard property

Re: [PATCH v4 01/30] drm/docs: Remove unused TV Standard property

[Noralf Trønnes]

Den 29.09.2022 18.30, skrev Maxime Ripard:
> That property is not used or exposed by any driver in the kernel. Remove
> it from the documentation.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 
> ---
> Changes in v4:
> - New patch
> ---
>  Documentation/gpu/kms-properties.csv | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/Documentation/gpu/kms-properties.csv b/Documentation/gpu/kms-properties.csv
> index 07ed22ea3bd6..45c12e3e82f4 100644
> --- a/Documentation/gpu/kms-properties.csv
> +++ b/Documentation/gpu/kms-properties.csv
> @@ -91,7 +91,6 @@ omap,Generic,“zorder”,RANGE,"Min=0, Max=3","CRTC, Plane",TBD
>  qxl,Generic,"“hotplug_mode_update""",RANGE,"Min=0, Max=1",Connector,TBD
>  radeon,DVI-I,“coherent”,RANGE,"Min=0, Max=1",Connector,TBD
>  ,DAC enable load detect,“load detection”,RANGE,"Min=0, Max=1",Connector,TBD
> -,TV Standard,"""tv standard""",ENUM,"{ ""ntsc"", ""pal"", ""pal-m"", ""pal-60"", ""ntsc-j"" , ""scart-pal"", ""pal-cn"", ""secam"" }",Connector,TBD

This property is listed under radeon and it is used in
drivers/gpu/drm/radeon/radeon_display.c

Noralf.

>  ,legacy TMDS PLL detect,"""tmds_pll""",ENUM,"{ ""driver"", ""bios"" }",-,TBD
>  ,Underscan,"""underscan""",ENUM,"{ ""off"", ""on"", ""auto"" }",Connector,TBD
>  ,,"""underscan hborder""",RANGE,"Min=0, Max=128",Connector,TBD
> 

Re: [PATCH v4 10/30] drm/connector: Add TV standard property

[Noralf Trønnes]

Den 29.09.2022 18.31, skrev Maxime Ripard:
> The TV mode property has been around for a while now to select and get the
> current TV mode output on an analog TV connector.
> 
> Despite that property name being generic, its content isn't and has been
> driver-specific which makes it hard to build any generic behaviour on top
> of it, both in kernel and user-space.
> 
> Let's create a new enum tv norm property, that can contain any of the
> analog TV standards currently supported by kernel drivers. Each driver can
> then pass in a bitmask of the modes it supports, and the property
> creation function will filter out the modes not supported.
> 
> We'll then be able to phase out the older tv mode property.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 
> ---
> Changes in v4:
> - Add property documentation to kms-properties.csv
> - Fix documentation
> ---
>  Documentation/gpu/kms-properties.csv |  1 +
>  drivers/gpu/drm/drm_atomic_uapi.c    |  4 +++
>  drivers/gpu/drm/drm_connector.c      | 57 +++++++++++++++++++++++++++++++-
>  include/drm/drm_connector.h          | 64 ++++++++++++++++++++++++++++++++++++
>  include/drm/drm_mode_config.h        |  8 +++++
>  5 files changed, 133 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/gpu/kms-properties.csv b/Documentation/gpu/kms-properties.csv
> index 45c12e3e82f4..3498bd5d5856 100644
> --- a/Documentation/gpu/kms-properties.csv
> +++ b/Documentation/gpu/kms-properties.csv
> @@ -91,6 +91,7 @@ omap,Generic,“zorder”,RANGE,"Min=0, Max=3","CRTC, Plane",TBD
>  qxl,Generic,"“hotplug_mode_update""",RANGE,"Min=0, Max=1",Connector,TBD
>  radeon,DVI-I,“coherent”,RANGE,"Min=0, Max=1",Connector,TBD
>  ,DAC enable load detect,“load detection”,RANGE,"Min=0, Max=1",Connector,TBD
> +,TV Mode,"""TV Mode""",ENUM,"{ ""NTSC"", ""NTSC-443"", ""NTSC-J"", ""PAL"", ""PAL-M"", ""PAL-N"", ""SECAM"" }",Connector,TBD
>  ,legacy TMDS PLL detect,"""tmds_pll""",ENUM,"{ ""driver"", ""bios"" }",-,TBD
>  ,Underscan,"""underscan""",ENUM,"{ ""off"", ""on"", ""auto"" }",Connector,TBD
>  ,,"""underscan hborder""",RANGE,"Min=0, Max=128",Connector,TBD

Turns out I was wrong about adding the property to this file, Daniel
says it's deprecated in f0f0657b108c ("drm/doc: Drop "content type" from
the legacy kms property table").

If you look at the Fixes commit it adds a kernel doc HDMI property
section and TV should probably have something like that.

Noralf.

Re: [PATCH v4 03/30] drm/tests: Add Kunit Helpers

[Noralf Trønnes]

Den 29.09.2022 18.30, skrev Maxime Ripard:
> As the number of kunit tests in KMS grows further, we start to have
> multiple test suites that, for example, need to register a mock DRM
> driver to interact with the KMS function they are supposed to test.
> 
> Let's add a file meant to provide those kind of helpers to avoid
> duplication.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 

Reviewed-by: Noralf Trønnes <noralf@tronnes.org>

Re: [PATCH v4 30/30] drm/sun4i: tv: Convert to the new TV mode property

[Noralf Trønnes]

Den 29.09.2022 18.31, skrev Maxime Ripard:
> Now that the core can deal fine with analog TV modes, let's convert the
> sun4i TV driver to leverage those new features.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---
>  drivers/gpu/drm/sun4i/sun4i_tv.c | 148 ++++++++++++++-------------------------
>  drivers/gpu/drm/vc4/vc4_vec.c    |   5 +-
>  2 files changed, 54 insertions(+), 99 deletions(-)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tv.c b/drivers/gpu/drm/sun4i/sun4i_tv.c

> @@ -467,35 +398,46 @@ static const struct drm_encoder_helper_funcs sun4i_tv_helper_funcs = {
>  
>  static int sun4i_tv_comp_get_modes(struct drm_connector *connector)
>  {
> -	int i;
> +	struct drm_display_mode *mode;
> +	int count = 0;
>  
> -	for (i = 0; i < ARRAY_SIZE(tv_modes); i++) {
> -		struct drm_display_mode *mode;
> -		const struct tv_mode *tv_mode = &tv_modes[i];
> -
> -		mode = drm_mode_create(connector->dev);
> -		if (!mode) {
> -			DRM_ERROR("Failed to create a new display mode\n");
> -			return 0;
> -		}
> +	mode = drm_mode_analog_ntsc_480i(connector->dev);
> +	if (!mode) {
> +		DRM_ERROR("Failed to create a new display mode\n");
> +		return -ENOMEM;
> +	}
>  
> -		strcpy(mode->name, tv_mode->name);
> +	mode->type |= DRM_MODE_TYPE_PREFERRED;
> +	drm_mode_probed_add(connector, mode);
> +	count += 1;
>  
> -		sun4i_tv_mode_to_drm_mode(tv_mode, mode);
> -		drm_mode_probed_add(connector, mode);
> +	mode = drm_mode_analog_pal_576i(connector->dev);
> +	if (!mode) {
> +		DRM_ERROR("Failed to create a new display mode\n");
> +		return -ENOMEM;
>  	}
>  
> -	return i;
> +	drm_mode_probed_add(connector, mode);
> +	count += 1;
> +
> +	return count;

count is always 2 so you can just return 2.

Acked-by: Noralf Trønnes <noralf@tronnes.org>

>  }

This stray hunk belongs to the vc4 TV mode patch I guess:

> diff --git a/drivers/gpu/drm/vc4/vc4_vec.c b/drivers/gpu/drm/vc4/vc4_vec.c
> index 8d37d7ba9b2a..88b4330bfa39 100644
> --- a/drivers/gpu/drm/vc4/vc4_vec.c
> +++ b/drivers/gpu/drm/vc4/vc4_vec.c
> @@ -322,7 +322,7 @@ vc4_vec_tv_mode_lookup(unsigned int mode)
>  	return NULL;
>  }
>  
> -static const struct drm_prop_enum_list tv_mode_names[] = {
> +static const struct drm_prop_enum_list legacy_tv_mode_names[] = {
>  	{ VC4_VEC_TV_MODE_NTSC, "NTSC", },
>  	{ VC4_VEC_TV_MODE_NTSC_443, "NTSC-443", },
>  	{ VC4_VEC_TV_MODE_NTSC_J, "NTSC-J", },
> @@ -498,7 +498,8 @@ static int vc4_vec_connector_init(struct drm_device *dev, struct vc4_vec *vec)
>  				   DRM_MODE_TV_MODE_NTSC);
>  
>  	prop = drm_property_create_enum(dev, 0, "mode",
> -					tv_mode_names, ARRAY_SIZE(tv_mode_names));
> +					legacy_tv_mode_names,
> +					ARRAY_SIZE(legacy_tv_mode_names));
>  	if (!prop)
>  		return -ENOMEM;
>  	vec->legacy_tv_mode_property = prop;
> 

Noralf.

Re: [PATCH v4 11/30] drm/modes: Add a function to generate analog display modes

[Noralf Trønnes]

Den 29.09.2022 18.31, skrev Maxime Ripard:
> Multiple drivers (meson, vc4, sun4i) define analog TV 525-lines and
> 625-lines modes in their drivers.
> 
> Since those modes are fairly standard, and that we'll need to use them
> in more places in the future, it makes sense to move their definition
> into the core framework.
> 
> However, analog display usually have fairly loose timings requirements,
> the only discrete parameters being the total number of lines and pixel
> clock frequency. Thus, we created a function that will create a display
> mode from the standard, the pixel frequency and the active area.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 
> ---
> 
> Changes in v4:
> - Reworded the line length check comment
> - Switch to HZ_PER_KHZ in tests
> - Use previous timing to fill our mode
> - Move the number of lines check earlier
> ---
>  drivers/gpu/drm/drm_modes.c            | 474 +++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/tests/Makefile         |   1 +
>  drivers/gpu/drm/tests/drm_modes_test.c | 144 ++++++++++
>  include/drm/drm_modes.h                |  17 ++
>  4 files changed, 636 insertions(+)
> 

I haven't followed the discussion on this patch, but it seems rather
excessive to add over 600 lines of code (including tests) to add 2 fixed
modes. And it's very difficult to see from the code what the actual
display mode timings really are, which would be useful for other
developers down the road wanting to use them.

Why not just hardcode the modes?

Noralf.

> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> index 304004fb80aa..7cf2fe98d7d2 100644
> --- a/drivers/gpu/drm/drm_modes.c
> +++ b/drivers/gpu/drm/drm_modes.c
> @@ -116,6 +116,480 @@ void drm_mode_probed_add(struct drm_connector *connector,
>  }
>  EXPORT_SYMBOL(drm_mode_probed_add);
>  
> +enum drm_mode_analog {
> +	DRM_MODE_ANALOG_NTSC, /* 525 lines, 60Hz */
> +	DRM_MODE_ANALOG_PAL, /* 625 lines, 50Hz */
> +};
> +
> +/*
> + * The timings come from:
> + * - https://web.archive.org/web/20220406232708/http://www.kolumbus.fi/pami1/video/pal_ntsc.html
> + * - https://web.archive.org/web/20220406124914/http://martin.hinner.info/vga/pal.html
> + * - https://web.archive.org/web/20220609202433/http://www.batsocks.co.uk/readme/video_timing.htm
> + */
> +#define NTSC_LINE_DURATION_NS		63556U
> +#define NTSC_LINES_NUMBER		525
> +
> +#define NTSC_HBLK_DURATION_TYP_NS	10900U
> +#define NTSC_HBLK_DURATION_MIN_NS	(NTSC_HBLK_DURATION_TYP_NS - 200)
> +#define NTSC_HBLK_DURATION_MAX_NS	(NTSC_HBLK_DURATION_TYP_NS + 200)
> +
> +#define NTSC_HACT_DURATION_TYP_NS	(NTSC_LINE_DURATION_NS - NTSC_HBLK_DURATION_TYP_NS)
> +#define NTSC_HACT_DURATION_MIN_NS	(NTSC_LINE_DURATION_NS - NTSC_HBLK_DURATION_MAX_NS)
> +#define NTSC_HACT_DURATION_MAX_NS	(NTSC_LINE_DURATION_NS - NTSC_HBLK_DURATION_MIN_NS)
> +
> +#define NTSC_HFP_DURATION_TYP_NS	1500
> +#define NTSC_HFP_DURATION_MIN_NS	1270
> +#define NTSC_HFP_DURATION_MAX_NS	2220
> +
> +#define NTSC_HSLEN_DURATION_TYP_NS	4700
> +#define NTSC_HSLEN_DURATION_MIN_NS	(NTSC_HSLEN_DURATION_TYP_NS - 100)
> +#define NTSC_HSLEN_DURATION_MAX_NS	(NTSC_HSLEN_DURATION_TYP_NS + 100)
> +
> +#define NTSC_HBP_DURATION_TYP_NS	4700
> +
> +/*
> + * I couldn't find the actual tolerance for the back porch, so let's
> + * just reuse the sync length ones.
> + */
> +#define NTSC_HBP_DURATION_MIN_NS	(NTSC_HBP_DURATION_TYP_NS - 100)
> +#define NTSC_HBP_DURATION_MAX_NS	(NTSC_HBP_DURATION_TYP_NS + 100)
> +
> +#define PAL_LINE_DURATION_NS		64000U
> +#define PAL_LINES_NUMBER		625
> +
> +#define PAL_HACT_DURATION_TYP_NS	51950U
> +#define PAL_HACT_DURATION_MIN_NS	(PAL_HACT_DURATION_TYP_NS - 100)
> +#define PAL_HACT_DURATION_MAX_NS	(PAL_HACT_DURATION_TYP_NS + 400)
> +
> +#define PAL_HBLK_DURATION_TYP_NS	(PAL_LINE_DURATION_NS - PAL_HACT_DURATION_TYP_NS)
> +#define PAL_HBLK_DURATION_MIN_NS	(PAL_LINE_DURATION_NS - PAL_HACT_DURATION_MAX_NS)
> +#define PAL_HBLK_DURATION_MAX_NS	(PAL_LINE_DURATION_NS - PAL_HACT_DURATION_MIN_NS)
> +
> +#define PAL_HFP_DURATION_TYP_NS		1650
> +#define PAL_HFP_DURATION_MIN_NS		(PAL_HFP_DURATION_TYP_NS - 100)
> +#define PAL_HFP_DURATION_MAX_NS		(PAL_HFP_DURATION_TYP_NS + 400)
> +
> +#define PAL_HSLEN_DURATION_TYP_NS	4700
> +#define PAL_HSLEN_DURATION_MIN_NS	(PAL_HSLEN_DURATION_TYP_NS - 200)
> +#define PAL_HSLEN_DURATION_MAX_NS	(PAL_HSLEN_DURATION_TYP_NS + 200)
> +
> +#define PAL_HBP_DURATION_TYP_NS		5700
> +#define PAL_HBP_DURATION_MIN_NS		(PAL_HBP_DURATION_TYP_NS - 200)
> +#define PAL_HBP_DURATION_MAX_NS		(PAL_HBP_DURATION_TYP_NS + 200)
> +
> +struct analog_param_field {
> +	unsigned int even, odd;
> +};
> +
> +#define PARAM_FIELD(_odd, _even)		\
> +	{ .even = _even, .odd = _odd }
> +
> +struct analog_param_range {
> +	unsigned int	min, typ, max;
> +};
> +
> +#define PARAM_RANGE(_min, _typ, _max)		\
> +	{ .min = _min, .typ = _typ, .max = _max }
> +
> +struct analog_parameters {
> +	unsigned int			num_lines;
> +	unsigned int			line_duration_ns;
> +
> +	struct analog_param_range	hact_ns;
> +	struct analog_param_range	hfp_ns;
> +	struct analog_param_range	hslen_ns;
> +	struct analog_param_range	hbp_ns;
> +	struct analog_param_range	hblk_ns;
> +
> +	unsigned int			bt601_hfp;
> +
> +	struct analog_param_field	vfp_lines;
> +	struct analog_param_field	vslen_lines;
> +	struct analog_param_field	vbp_lines;
> +};
> +
> +#define TV_MODE_PARAMETER(_mode, _lines, _line_dur, _hact, _hfp, _hslen, _hbp, _hblk, _bt601_hfp, _vfp, _vslen, _vbp) \
> +	[_mode] = {							\
> +		.num_lines = _lines,					\
> +		.line_duration_ns = _line_dur,				\
> +		.hact_ns = _hact,					\
> +		.hfp_ns = _hfp,						\
> +		.hslen_ns = _hslen,					\
> +		.hbp_ns = _hbp,						\
> +		.hblk_ns = _hblk,					\
> +		.bt601_hfp = _bt601_hfp,				\
> +		.vfp_lines = _vfp,					\
> +		.vslen_lines = _vslen,					\
> +		.vbp_lines = _vbp,					\
> +	}
> +
> +const static struct analog_parameters tv_modes_parameters[] = {
> +	TV_MODE_PARAMETER(DRM_MODE_ANALOG_NTSC,
> +			  NTSC_LINES_NUMBER,
> +			  NTSC_LINE_DURATION_NS,
> +			  PARAM_RANGE(NTSC_HACT_DURATION_MIN_NS,
> +				      NTSC_HACT_DURATION_TYP_NS,
> +				      NTSC_HACT_DURATION_MAX_NS),
> +			  PARAM_RANGE(NTSC_HFP_DURATION_MIN_NS,
> +				      NTSC_HFP_DURATION_TYP_NS,
> +				      NTSC_HFP_DURATION_MAX_NS),
> +			  PARAM_RANGE(NTSC_HSLEN_DURATION_MIN_NS,
> +				      NTSC_HSLEN_DURATION_TYP_NS,
> +				      NTSC_HSLEN_DURATION_MAX_NS),
> +			  PARAM_RANGE(NTSC_HBP_DURATION_MIN_NS,
> +				      NTSC_HBP_DURATION_TYP_NS,
> +				      NTSC_HBP_DURATION_MAX_NS),
> +			  PARAM_RANGE(NTSC_HBLK_DURATION_MIN_NS,
> +				      NTSC_HBLK_DURATION_TYP_NS,
> +				      NTSC_HBLK_DURATION_MAX_NS),
> +			  16,
> +			  PARAM_FIELD(3, 3),
> +			  PARAM_FIELD(3, 3),
> +			  PARAM_FIELD(16, 17)),
> +	TV_MODE_PARAMETER(DRM_MODE_ANALOG_PAL,
> +			  PAL_LINES_NUMBER,
> +			  PAL_LINE_DURATION_NS,
> +			  PARAM_RANGE(PAL_HACT_DURATION_MIN_NS,
> +				      PAL_HACT_DURATION_TYP_NS,
> +				      PAL_HACT_DURATION_MAX_NS),
> +			  PARAM_RANGE(PAL_HFP_DURATION_MIN_NS,
> +				      PAL_HFP_DURATION_TYP_NS,
> +				      PAL_HFP_DURATION_MAX_NS),
> +			  PARAM_RANGE(PAL_HSLEN_DURATION_MIN_NS,
> +				      PAL_HSLEN_DURATION_TYP_NS,
> +				      PAL_HSLEN_DURATION_MAX_NS),
> +			  PARAM_RANGE(PAL_HBP_DURATION_MIN_NS,
> +				      PAL_HBP_DURATION_TYP_NS,
> +				      PAL_HBP_DURATION_MAX_NS),
> +			  PARAM_RANGE(PAL_HBLK_DURATION_MIN_NS,
> +				      PAL_HBLK_DURATION_TYP_NS,
> +				      PAL_HBLK_DURATION_MAX_NS),
> +			  12,
> +
> +			  /*
> +			   * The front porch is actually 6 short sync
> +			   * pulses for the even field, and 5 for the
> +			   * odd field. Each sync takes half a life so
> +			   * the odd field front porch is shorter by
> +			   * half a line.
> +			   *
> +			   * In progressive, we're supposed to use 6
> +			   * pulses, so we're fine there
> +			   */
> +			  PARAM_FIELD(3, 2),
> +
> +			  /*
> +			   * The vsync length is 5 long sync pulses,
> +			   * each field taking half a line. We're
> +			   * shorter for both fields by half a line.
> +			   *
> +			   * In progressive, we're supposed to use 5
> +			   * pulses, so we're off by half
> +			   * a line.
> +			   *
> +			   * In interlace, we're now off by half a line
> +			   * for the even field and one line for the odd
> +			   * field.
> +			   */
> +			  PARAM_FIELD(3, 3),
> +
> +			  /*
> +			   * The back porch starts with post-equalizing
> +			   * pulses, consisting in 5 short sync pulses
> +			   * for the even field, 4 for the odd field. In
> +			   * progressive, it's 5 short syncs.
> +			   *
> +			   * In progressive, we thus have 2.5 lines,
> +			   * plus the 0.5 line we were missing
> +			   * previously, so we should use 3 lines.
> +			   *
> +			   * In interlace, the even field is in the
> +			   * exact same case than progressive. For the
> +			   * odd field, we should be using 2 lines but
> +			   * we're one line short, so we'll make up for
> +			   * it here by using 3.
> +			   *
> +			   * The entire blanking area is supposed to
> +			   * take 25 lines, so we also need to account
> +			   * for the rest of the blanking area that
> +			   * can't be in either the front porch or sync
> +			   * period.
> +			   */
> +			  PARAM_FIELD(19, 20)),
> +};
> +
> +static int fill_analog_mode(struct drm_device *dev,
> +			    struct drm_display_mode *mode,
> +			    const struct analog_parameters *params,
> +			    unsigned long pixel_clock_hz,
> +			    unsigned int hactive,
> +			    unsigned int vactive,
> +			    bool interlace)
> +{
> +	unsigned long pixel_duration_ns = NSEC_PER_SEC / pixel_clock_hz;
> +	unsigned int htotal, vtotal;
> +	unsigned int max_hact, hact_duration_ns;
> +	unsigned int hblk, hblk_duration_ns;
> +	unsigned int hfp, hfp_duration_ns;
> +	unsigned int hslen, hslen_duration_ns;
> +	unsigned int hbp, hbp_duration_ns;
> +	unsigned int porches, porches_duration_ns;
> +	unsigned int vfp, vfp_min;
> +	unsigned int vbp, vbp_min;
> +	unsigned int vslen;
> +	bool bt601 = false;
> +	int porches_rem;
> +	u64 result;
> +
> +	drm_dbg_kms(dev,
> +		    "Generating a %ux%u%c, %u-line mode with a %lu kHz clock\n",
> +		    hactive, vactive,
> +		    interlace ? 'i' : 'p',
> +		    params->num_lines,
> +		    pixel_clock_hz / 1000);
> +
> +	max_hact = params->hact_ns.max / pixel_duration_ns;
> +	if (pixel_clock_hz == 13500000 && hactive > max_hact && hactive <= 720) {
> +		drm_dbg_kms(dev, "Trying to generate a BT.601 mode. Disabling checks.\n");
> +		bt601 = true;
> +	}
> +
> +	/*
> +	 * Our pixel duration is going to be round down by the division,
> +	 * so rounding up is probably going to introduce even more
> +	 * deviation.
> +	 */
> +	result = (u64)params->line_duration_ns * pixel_clock_hz;
> +	do_div(result, NSEC_PER_SEC);
> +	htotal = result;
> +
> +	drm_dbg_kms(dev, "Total Horizontal Number of Pixels: %u\n", htotal);
> +
> +	hact_duration_ns = hactive * pixel_duration_ns;
> +	if (!bt601 &&
> +	    (hact_duration_ns < params->hact_ns.min ||
> +	     hact_duration_ns > params->hact_ns.max)) {
> +		DRM_ERROR("Invalid horizontal active area duration: %uns (min: %u, max %u)\n",
> +			  hact_duration_ns, params->hact_ns.min, params->hact_ns.max);
> +		return -EINVAL;
> +	}
> +
> +	hblk = htotal - hactive;
> +	drm_dbg_kms(dev, "Horizontal Blanking Period: %u\n", hblk);
> +
> +	hblk_duration_ns = hblk * pixel_duration_ns;
> +	if (!bt601 &&
> +	    (hblk_duration_ns < params->hblk_ns.min ||
> +	     hblk_duration_ns > params->hblk_ns.max)) {
> +		DRM_ERROR("Invalid horizontal blanking duration: %uns (min: %u, max %u)\n",
> +			  hblk_duration_ns, params->hblk_ns.min, params->hblk_ns.max);
> +		return -EINVAL;
> +	}
> +
> +	hslen = DIV_ROUND_UP(params->hslen_ns.typ, pixel_duration_ns);
> +	drm_dbg_kms(dev, "Horizontal Sync Period: %u\n", hslen);
> +
> +	hslen_duration_ns = hslen * pixel_duration_ns;
> +	if (!bt601 &&
> +	    (hslen_duration_ns < params->hslen_ns.min ||
> +	     hslen_duration_ns > params->hslen_ns.max)) {
> +		DRM_ERROR("Invalid horizontal sync duration: %uns (min: %u, max %u)\n",
> +			  hslen_duration_ns, params->hslen_ns.min, params->hslen_ns.max);
> +		return -EINVAL;
> +	}
> +
> +	porches = hblk - hslen;
> +	drm_dbg_kms(dev, "Remaining horizontal pixels for both porches: %u\n", porches);
> +
> +	porches_duration_ns = porches * pixel_duration_ns;
> +	if (!bt601 &&
> +	    (porches_duration_ns > (params->hfp_ns.max + params->hbp_ns.max) ||
> +	     porches_duration_ns < (params->hfp_ns.min + params->hbp_ns.min))) {
> +		DRM_ERROR("Invalid horizontal porches duration: %uns\n", porches_duration_ns);
> +		return -EINVAL;
> +	}
> +
> +	if (bt601) {
> +		hfp = params->bt601_hfp;
> +	} else {
> +		unsigned int hfp_min = DIV_ROUND_UP(params->hfp_ns.min,
> +						    pixel_duration_ns);
> +		unsigned int hbp_min = DIV_ROUND_UP(params->hbp_ns.min,
> +						    pixel_duration_ns);
> +		 int porches_rem = porches - hfp_min - hbp_min;
> +
> +		hfp = hfp_min + DIV_ROUND_UP(porches_rem, 2);
> +	}
> +
> +	drm_dbg_kms(dev, "Horizontal Front Porch: %u\n", hfp);
> +
> +	hfp_duration_ns = hfp * pixel_duration_ns;
> +	if (!bt601 &&
> +	    (hfp_duration_ns < params->hfp_ns.min ||
> +	     hfp_duration_ns > params->hfp_ns.max)) {
> +		DRM_ERROR("Invalid horizontal front porch duration: %uns (min: %u, max %u)\n",
> +			  hfp_duration_ns, params->hfp_ns.min, params->hfp_ns.max);
> +		return -EINVAL;
> +	}
> +
> +	hbp = porches - hfp;
> +	drm_dbg_kms(dev, "Horizontal Back Porch: %u\n", hbp);
> +
> +	hbp_duration_ns = hbp * pixel_duration_ns;
> +	if (!bt601 &&
> +	    (hbp_duration_ns < params->hbp_ns.min ||
> +	     hbp_duration_ns > params->hbp_ns.max)) {
> +		DRM_ERROR("Invalid horizontal back porch duration: %uns (min: %u, max %u)\n",
> +			  hbp_duration_ns, params->hbp_ns.min, params->hbp_ns.max);
> +		return -EINVAL;
> +	}
> +
> +	if (htotal != (hactive + hfp + hslen + hbp))
> +		return -EINVAL;
> +
> +	mode->clock = pixel_clock_hz / 1000;
> +	mode->hdisplay = hactive;
> +	mode->hsync_start = mode->hdisplay + hfp;
> +	mode->hsync_end = mode->hsync_start + hslen;
> +	mode->htotal = mode->hsync_end + hbp;
> +
> +	if (interlace) {
> +		vfp_min = params->vfp_lines.even + params->vfp_lines.odd;
> +		vbp_min = params->vbp_lines.even + params->vbp_lines.odd;
> +		vslen = params->vslen_lines.even + params->vslen_lines.odd;
> +	} else {
> +		/*
> +		 * By convention, NSTC (aka 525/60) systems start with
> +		 * the even field, but PAL (aka 625/50) systems start
> +		 * with the odd one.
> +		 *
> +		 * PAL systems also have asymetric timings between the
> +		 * even and odd field, while NTSC is symetric.
> +		 *
> +		 * Moreover, if we want to create a progressive mode for
> +		 * PAL, we need to use the odd field timings.
> +		 *
> +		 * Since odd == even for NTSC, we can just use the odd
> +		 * one all the time to simplify the code a bit.
> +		 */
> +		vfp_min = params->vfp_lines.odd;
> +		vbp_min = params->vbp_lines.odd;
> +		vslen = params->vslen_lines.odd;
> +	}
> +
> +	drm_dbg_kms(dev, "Vertical Sync Period: %u\n", vslen);
> +
> +	porches = params->num_lines - vactive - vslen;
> +	drm_dbg_kms(dev, "Remaining vertical pixels for both porches: %u\n", porches);
> +
> +	porches_rem = porches - vfp_min - vbp_min;
> +	vfp = vfp_min + (porches_rem / 2);
> +	drm_dbg_kms(dev, "Vertical Front Porch: %u\n", vfp);
> +
> +	vbp = porches - vfp;
> +	drm_dbg_kms(dev, "Vertical Back Porch: %u\n", vbp);
> +
> +	vtotal = vactive + vfp + vslen + vbp;
> +	if (params->num_lines != vtotal) {
> +		DRM_ERROR("Invalid vertical total: %upx (expected %upx)\n",
> +			  vtotal, params->num_lines);
> +		return -EINVAL;
> +	}
> +
> +	mode->vdisplay = vactive;
> +	mode->vsync_start = mode->vdisplay + vfp;
> +	mode->vsync_end = mode->vsync_start + vslen;
> +	mode->vtotal = mode->vsync_end + vbp;
> +
> +	if (mode->vtotal != params->num_lines)
> +		return -EINVAL;
> +
> +	mode->type = DRM_MODE_TYPE_DRIVER;
> +	mode->flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC;
> +	if (interlace)
> +		mode->flags |= DRM_MODE_FLAG_INTERLACE;
> +
> +	drm_mode_set_name(mode);
> +
> +	drm_dbg_kms(dev, "Generated mode " DRM_MODE_FMT "\n", DRM_MODE_ARG(mode));
> +
> +	return 0;
> +}
> +
> +/**
> + * drm_analog_tv_mode - create a display mode for an analog TV
> + * @dev: drm device
> + * @tv_mode: TV Mode standard to create a mode for. See DRM_MODE_TV_MODE_*.
> + * @pixel_clock_hz: Pixel Clock Frequency, in Hertz
> + * @hdisplay: hdisplay size
> + * @vdisplay: vdisplay size
> + * @interlace: whether to compute an interlaced mode
> + *
> + * This function creates a struct drm_display_mode instance suited for
> + * an analog TV output, for one of the usual analog TV mode.
> + *
> + * Note that @hdisplay is larger than the usual constraints for the PAL
> + * and NTSC timings, and we'll choose to ignore most timings constraints
> + * to reach those resolutions.
> + *
> + * Returns:
> + *
> + * A pointer to the mode, allocated with drm_mode_create(). Returns NULL
> + * on error.
> + */
> +struct drm_display_mode *drm_analog_tv_mode(struct drm_device *dev,
> +					    enum drm_connector_tv_mode tv_mode,
> +					    unsigned long pixel_clock_hz,
> +					    unsigned int hdisplay,
> +					    unsigned int vdisplay,
> +					    bool interlace)
> +{
> +	struct drm_display_mode *mode;
> +	enum drm_mode_analog analog;
> +	int ret;
> +
> +	switch (tv_mode) {
> +	case DRM_MODE_TV_MODE_NTSC:
> +		fallthrough;
> +	case DRM_MODE_TV_MODE_NTSC_443:
> +		fallthrough;
> +	case DRM_MODE_TV_MODE_NTSC_J:
> +		fallthrough;
> +	case DRM_MODE_TV_MODE_PAL_M:
> +		analog = DRM_MODE_ANALOG_NTSC;
> +		break;
> +
> +	case DRM_MODE_TV_MODE_PAL:
> +		fallthrough;
> +	case DRM_MODE_TV_MODE_PAL_N:
> +		fallthrough;
> +	case DRM_MODE_TV_MODE_SECAM:
> +		analog = DRM_MODE_ANALOG_PAL;
> +		break;
> +
> +	default:
> +		return NULL;
> +	}
> +
> +	mode = drm_mode_create(dev);
> +	if (!mode)
> +		return NULL;
> +
> +	ret = fill_analog_mode(dev, mode,
> +			       &tv_modes_parameters[analog],
> +			       pixel_clock_hz, hdisplay, vdisplay, interlace);
> +	if (ret)
> +		goto err_free_mode;
> +
> +	return mode;
> +
> +err_free_mode:
> +	drm_mode_destroy(dev, mode);
> +	return NULL;
> +}
> +EXPORT_SYMBOL(drm_analog_tv_mode);
> +
>  /**
>   * drm_cvt_mode -create a modeline based on the CVT algorithm
>   * @dev: drm device
> diff --git a/drivers/gpu/drm/tests/Makefile b/drivers/gpu/drm/tests/Makefile
> index b29ef1085cad..b22ac96fdd65 100644
> --- a/drivers/gpu/drm/tests/Makefile
> +++ b/drivers/gpu/drm/tests/Makefile
> @@ -10,5 +10,6 @@ obj-$(CONFIG_DRM_KUNIT_TEST) += \
>  	drm_framebuffer_test.o \
>  	drm_kunit_helpers.o \
>  	drm_mm_test.o \
> +	drm_modes_test.o \
>  	drm_plane_helper_test.o \
>  	drm_rect_test.o
> diff --git a/drivers/gpu/drm/tests/drm_modes_test.c b/drivers/gpu/drm/tests/drm_modes_test.c
> new file mode 100644
> index 000000000000..550e3b95453e
> --- /dev/null
> +++ b/drivers/gpu/drm/tests/drm_modes_test.c
> @@ -0,0 +1,144 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Kunit test for drm_modes functions
> + */
> +
> +#include <drm/drm_modes.h>
> +
> +#include <kunit/test.h>
> +
> +#include <linux/units.h>
> +
> +#include "drm_kunit_helpers.h"
> +
> +struct drm_modes_test_priv {
> +	struct drm_device *drm;
> +};
> +
> +static int drm_modes_test_init(struct kunit *test)
> +{
> +	struct drm_modes_test_priv *priv;
> +
> +	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, priv);
> +
> +	priv->drm = drm_kunit_device_init(test, "drm-modes-test");
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->drm);
> +
> +	test->priv = priv;
> +
> +	return 0;
> +}
> +
> +static void drm_modes_analog_tv_ntsc_480i(struct kunit *test)
> +{
> +	struct drm_modes_test_priv *priv = test->priv;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_analog_tv_mode(priv->drm,
> +				  DRM_MODE_TV_MODE_NTSC,
> +				  13500 * HZ_PER_KHZ, 720, 480,
> +				  true);
> +	KUNIT_ASSERT_NOT_NULL(test, mode);
> +
> +	KUNIT_EXPECT_EQ(test, drm_mode_vrefresh(mode), 60);
> +	KUNIT_EXPECT_EQ(test, mode->hdisplay, 720);
> +
> +	/* BT.601 defines hsync_start at 736 for 480i */
> +	KUNIT_EXPECT_EQ(test, mode->hsync_start, 736);
> +
> +	/*
> +	 * The NTSC standard expects a line to take 63.556us. With a
> +	 * pixel clock of 13.5 MHz, a pixel takes around 74ns, so we
> +	 * need to have 63556ns / 74ns = 858.
> +	 *
> +	 * This is also mandated by BT.601.
> +	 */
> +	KUNIT_EXPECT_EQ(test, mode->htotal, 858);
> +
> +	KUNIT_EXPECT_EQ(test, mode->vdisplay, 480);
> +	KUNIT_EXPECT_EQ(test, mode->vtotal, 525);
> +}
> +
> +static void drm_modes_analog_tv_ntsc_480i_inlined(struct kunit *test)
> +{
> +	struct drm_modes_test_priv *priv = test->priv;
> +	struct drm_display_mode *expected, *mode;
> +
> +	expected = drm_analog_tv_mode(priv->drm,
> +				      DRM_MODE_TV_MODE_NTSC,
> +				      13500 * HZ_PER_KHZ, 720, 480,
> +				      true);
> +	KUNIT_ASSERT_NOT_NULL(test, expected);
> +
> +	mode = drm_mode_analog_ntsc_480i(priv->drm);
> +	KUNIT_ASSERT_NOT_NULL(test, mode);
> +
> +	KUNIT_EXPECT_TRUE(test, drm_mode_equal(expected, mode));
> +}
> +
> +static void drm_modes_analog_tv_pal_576i(struct kunit *test)
> +{
> +	struct drm_modes_test_priv *priv = test->priv;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_analog_tv_mode(priv->drm,
> +				  DRM_MODE_TV_MODE_PAL,
> +				  13500 * HZ_PER_KHZ, 720, 576,
> +				  true);
> +	KUNIT_ASSERT_NOT_NULL(test, mode);
> +
> +	KUNIT_EXPECT_EQ(test, drm_mode_vrefresh(mode), 50);
> +	KUNIT_EXPECT_EQ(test, mode->hdisplay, 720);
> +
> +	/* BT.601 defines hsync_start at 732 for 576i */
> +	KUNIT_EXPECT_EQ(test, mode->hsync_start, 732);
> +
> +	/*
> +	 * The PAL standard expects a line to take 64us. With a pixel
> +	 * clock of 13.5 MHz, a pixel takes around 74ns, so we need to
> +	 * have 64000ns / 74ns = 864.
> +	 *
> +	 * This is also mandated by BT.601.
> +	 */
> +	KUNIT_EXPECT_EQ(test, mode->htotal, 864);
> +
> +	KUNIT_EXPECT_EQ(test, mode->vdisplay, 576);
> +	KUNIT_EXPECT_EQ(test, mode->vtotal, 625);
> +}
> +
> +static void drm_modes_analog_tv_pal_576i_inlined(struct kunit *test)
> +{
> +	struct drm_modes_test_priv *priv = test->priv;
> +	struct drm_display_mode *expected, *mode;
> +
> +	expected = drm_analog_tv_mode(priv->drm,
> +				      DRM_MODE_TV_MODE_PAL,
> +				      13500 * HZ_PER_KHZ, 720, 576,
> +				      true);
> +	KUNIT_ASSERT_NOT_NULL(test, expected);
> +
> +	mode = drm_mode_analog_pal_576i(priv->drm);
> +	KUNIT_ASSERT_NOT_NULL(test, mode);
> +
> +	KUNIT_EXPECT_TRUE(test, drm_mode_equal(expected, mode));
> +}
> +
> +static struct kunit_case drm_modes_analog_tv_tests[] = {
> +	KUNIT_CASE(drm_modes_analog_tv_ntsc_480i),
> +	KUNIT_CASE(drm_modes_analog_tv_ntsc_480i_inlined),
> +	KUNIT_CASE(drm_modes_analog_tv_pal_576i),
> +	KUNIT_CASE(drm_modes_analog_tv_pal_576i_inlined),
> +	{ }
> +};
> +
> +static struct kunit_suite drm_modes_analog_tv_test_suite = {
> +	.name = "drm_modes_analog_tv",
> +	.init = drm_modes_test_init,
> +	.test_cases = drm_modes_analog_tv_tests,
> +};
> +
> +kunit_test_suites(
> +	&drm_modes_analog_tv_test_suite
> +);
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
> index b0c680e6f670..c613f0abe9dc 100644
> --- a/include/drm/drm_modes.h
> +++ b/include/drm/drm_modes.h
> @@ -468,6 +468,23 @@ bool drm_mode_is_420_also(const struct drm_display_info *display,
>  bool drm_mode_is_420(const struct drm_display_info *display,
>  		     const struct drm_display_mode *mode);
>  
> +struct drm_display_mode *drm_analog_tv_mode(struct drm_device *dev,
> +					    enum drm_connector_tv_mode mode,
> +					    unsigned long pixel_clock_hz,
> +					    unsigned int hdisplay,
> +					    unsigned int vdisplay,
> +					    bool interlace);
> +
> +static inline struct drm_display_mode *drm_mode_analog_ntsc_480i(struct drm_device *dev)
> +{
> +	return drm_analog_tv_mode(dev, DRM_MODE_TV_MODE_NTSC, 13500000, 720, 480, true);
> +}
> +
> +static inline struct drm_display_mode *drm_mode_analog_pal_576i(struct drm_device *dev)
> +{
> +	return drm_analog_tv_mode(dev, DRM_MODE_TV_MODE_PAL, 13500000, 720, 576, true);
> +}
> +
>  struct drm_display_mode *drm_cvt_mode(struct drm_device *dev,
>  				      int hdisplay, int vdisplay, int vrefresh,
>  				      bool reduced, bool interlaced,
> 

Re: [PATCH v4 11/30] drm/modes: Add a function to generate analog display modes

[Maxime Ripard]

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Hi Noralf,

On Sat, Oct 01, 2022 at 02:52:06PM +0200, Noralf Trønnes wrote:
> Den 29.09.2022 18.31, skrev Maxime Ripard:
> > Multiple drivers (meson, vc4, sun4i) define analog TV 525-lines and
> > 625-lines modes in their drivers.
> > 
> > Since those modes are fairly standard, and that we'll need to use them
> > in more places in the future, it makes sense to move their definition
> > into the core framework.
> > 
> > However, analog display usually have fairly loose timings requirements,
> > the only discrete parameters being the total number of lines and pixel
> > clock frequency. Thus, we created a function that will create a display
> > mode from the standard, the pixel frequency and the active area.
> > 
> > Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> > 
> > ---
> > 
> > Changes in v4:
> > - Reworded the line length check comment
> > - Switch to HZ_PER_KHZ in tests
> > - Use previous timing to fill our mode
> > - Move the number of lines check earlier
> > ---
> >  drivers/gpu/drm/drm_modes.c            | 474 +++++++++++++++++++++++++++++++++
> >  drivers/gpu/drm/tests/Makefile         |   1 +
> >  drivers/gpu/drm/tests/drm_modes_test.c | 144 ++++++++++
> >  include/drm/drm_modes.h                |  17 ++
> >  4 files changed, 636 insertions(+)
> > 
> 
> I haven't followed the discussion on this patch, but it seems rather
> excessive to add over 600 lines of code (including tests) to add 2 fixed
> modes. And it's very difficult to see from the code what the actual
> display mode timings really are, which would be useful for other
> developers down the road wanting to use them.
> 
> Why not just hardcode the modes?

Yeah, I have kind of the same feeling tbh, but it was asked back on the
v1 to ease the transition of old fbdev drivers, since they will need
such a function:
https://lore.kernel.org/dri-devel/CAMuHMdUrwzPYjA0wdR7ADj5Ov6+m03JbnY8fBYzRYyWDuNm5=g@mail.gmail.com/

Maxime

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Re: [PATCH v4 11/30] drm/modes: Add a function to generate analog display modes

[Noralf Trønnes]

Den 13.10.2022 10.36, skrev Maxime Ripard:
> Hi Noralf,
> 
> On Sat, Oct 01, 2022 at 02:52:06PM +0200, Noralf Trønnes wrote:
>> Den 29.09.2022 18.31, skrev Maxime Ripard:
>>> Multiple drivers (meson, vc4, sun4i) define analog TV 525-lines and
>>> 625-lines modes in their drivers.
>>>
>>> Since those modes are fairly standard, and that we'll need to use them
>>> in more places in the future, it makes sense to move their definition
>>> into the core framework.
>>>
>>> However, analog display usually have fairly loose timings requirements,
>>> the only discrete parameters being the total number of lines and pixel
>>> clock frequency. Thus, we created a function that will create a display
>>> mode from the standard, the pixel frequency and the active area.
>>>
>>> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
>>>
>>> ---
>>>
>>> Changes in v4:
>>> - Reworded the line length check comment
>>> - Switch to HZ_PER_KHZ in tests
>>> - Use previous timing to fill our mode
>>> - Move the number of lines check earlier
>>> ---
>>>  drivers/gpu/drm/drm_modes.c            | 474 +++++++++++++++++++++++++++++++++
>>>  drivers/gpu/drm/tests/Makefile         |   1 +
>>>  drivers/gpu/drm/tests/drm_modes_test.c | 144 ++++++++++
>>>  include/drm/drm_modes.h                |  17 ++
>>>  4 files changed, 636 insertions(+)
>>>
>>
>> I haven't followed the discussion on this patch, but it seems rather
>> excessive to add over 600 lines of code (including tests) to add 2 fixed
>> modes. And it's very difficult to see from the code what the actual
>> display mode timings really are, which would be useful for other
>> developers down the road wanting to use them.
>>
>> Why not just hardcode the modes?
> 
> Yeah, I have kind of the same feeling tbh, but it was asked back on the
> v1 to ease the transition of old fbdev drivers, since they will need
> such a function:
> https://lore.kernel.org/dri-devel/CAMuHMdUrwzPYjA0wdR7ADj5Ov6+m03JbnY8fBYzRYyWDuNm5=g@mail.gmail.com/
> 

If that's the case I suggest you just hardcode them for now and leave
the complexity to the developer doing the actual conversion of the fbdev
driver. Who knows when that will happen, but that person will have your
well documented and discussed work to fall back on.

Noralf.

Re: [PATCH v4 11/30] drm/modes: Add a function to generate analog display modes

[Maxime Ripard]

Hi,

On Sat, Oct 15, 2022 at 05:04:50PM +0200, Noralf Trønnes wrote:
> Den 13.10.2022 10.36, skrev Maxime Ripard:
> > On Sat, Oct 01, 2022 at 02:52:06PM +0200, Noralf Trønnes wrote:
> >> Den 29.09.2022 18.31, skrev Maxime Ripard:
> >>> Multiple drivers (meson, vc4, sun4i) define analog TV 525-lines and
> >>> 625-lines modes in their drivers.
> >>>
> >>> Since those modes are fairly standard, and that we'll need to use them
> >>> in more places in the future, it makes sense to move their definition
> >>> into the core framework.
> >>>
> >>> However, analog display usually have fairly loose timings requirements,
> >>> the only discrete parameters being the total number of lines and pixel
> >>> clock frequency. Thus, we created a function that will create a display
> >>> mode from the standard, the pixel frequency and the active area.
> >>>
> >>> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> >>>
> >>> ---
> >>>
> >>> Changes in v4:
> >>> - Reworded the line length check comment
> >>> - Switch to HZ_PER_KHZ in tests
> >>> - Use previous timing to fill our mode
> >>> - Move the number of lines check earlier
> >>> ---
> >>>  drivers/gpu/drm/drm_modes.c            | 474 +++++++++++++++++++++++++++++++++
> >>>  drivers/gpu/drm/tests/Makefile         |   1 +
> >>>  drivers/gpu/drm/tests/drm_modes_test.c | 144 ++++++++++
> >>>  include/drm/drm_modes.h                |  17 ++
> >>>  4 files changed, 636 insertions(+)
> >>>
> >>
> >> I haven't followed the discussion on this patch, but it seems rather
> >> excessive to add over 600 lines of code (including tests) to add 2 fixed
> >> modes. And it's very difficult to see from the code what the actual
> >> display mode timings really are, which would be useful for other
> >> developers down the road wanting to use them.
> >>
> >> Why not just hardcode the modes?
> > 
> > Yeah, I have kind of the same feeling tbh, but it was asked back on the
> > v1 to ease the transition of old fbdev drivers, since they will need
> > such a function:
> > https://lore.kernel.org/dri-devel/CAMuHMdUrwzPYjA0wdR7ADj5Ov6+m03JbnY8fBYzRYyWDuNm5=g@mail.gmail.com/
> > 
> 
> If that's the case I suggest you just hardcode them for now and leave
> the complexity to the developer doing the actual conversion of the fbdev
> driver. Who knows when that will happen, but that person will have your
> well documented and discussed work to fall back on.

I'd rather not, tbh. We've collectively spent weeks figuring this out,
reviewing it and so on, I very much want to avoid doing this all over
again if it's going to be useful at some point.

Jani also wanted to expose a function and not a raw mode, so this patch
also addresses that:
https://lore.kernel.org/dri-devel/8735eeg31e.fsf@intel.com/

Maxime

Re: [PATCH v4 00/30] drm: Analog TV Improvements

[Noralf Trønnes]

Den 29.09.2022 18.30, skrev Maxime Ripard:
> Hi,
> 
> Here's a series aiming at improving the command line named modes support,
> and more importantly how we deal with all the analog TV variants.
> 
> The named modes support were initially introduced to allow to specify the
> analog TV mode to be used.
> 
> However, this was causing multiple issues:
> 
>   * The mode name parsed on the command line was passed directly to the
>     driver, which had to figure out which mode it was suppose to match;
> 
>   * Figuring that out wasn't really easy, since the video= argument or what
>     the userspace might not even have a name in the first place, but
>     instead could have passed a mode with the same timings;
> 
>   * The fallback to matching on the timings was mostly working as long as
>     we were supporting one 525 lines (most likely NSTC) and one 625 lines
>     (PAL), but couldn't differentiate between two modes with the same
>     timings (NTSC vs PAL-M vs NSTC-J for example);
> 
>   * There was also some overlap with the tv mode property registered by
>     drm_mode_create_tv_properties(), but named modes weren't interacting
>     with that property at all.
> 
>   * Even though that property was generic, its possible values were
>     specific to each drivers, which made some generic support difficult.
> 
> Thus, I chose to tackle in multiple steps:
> 
>   * A new TV mode property was introduced, with generic values, each driver
>     reporting through a bitmask what standard it supports to the userspace;
> 
>   * This option was added to the command line parsing code to be able to
>     specify it on the kernel command line, and new atomic_check and reset
>     helpers were created to integrate properly into atomic KMS;
> 
>   * The named mode parsing code is now creating a proper display mode for
>     the given named mode, and the TV standard will thus be part of the
>     connector state;
> 
>   * Two drivers were converted and tested for now (vc4 and sun4i), with
>     some backward compatibility code to translate the old TV mode to the
>     new TV mode;
> 
> Unit tests were created along the way.
> 
> One can switch from NTSC to PAL now using (on vc4)
> 
> modetest -M vc4  -s 53:720x480i -w 53:'TV mode':1 # NTSC
> modetest -M vc4  -s 53:720x576i -w 53:'TV mode':4 # PAL
> 
> Let me know what you think,
> Maxime
> 

I suggest that you apply the patches that are reviewed, have merrit on
their own and are not tied to the TV mode property.
This will help in keeping this rather big patchset focused and ease the
task for reviewers.

The following seems to be in that group:

  drm/tests: Order Kunit tests in Makefile
  drm/atomic-helper: Rename drm_atomic_helper_connector_tv_reset to
avoid ambiguity
  drm/connector: Rename subconnector state variable
  drm/atomic: Add TV subconnector property to get/set_property
  drm/modes: Only consider bpp and refresh before options
  drm/modes: parse_cmdline: Add support for named modes containing dashes
  drm/vc4: vec: Fix definition of PAL-M mode

Noralf.

Re: [PATCH v4 00/30] drm: Analog TV Improvements

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 3439 bytes --]

On Sat, Oct 01, 2022 at 03:12:06PM +0200, Noralf Trønnes wrote:
> 
> 
> Den 29.09.2022 18.30, skrev Maxime Ripard:
> > Hi,
> > 
> > Here's a series aiming at improving the command line named modes support,
> > and more importantly how we deal with all the analog TV variants.
> > 
> > The named modes support were initially introduced to allow to specify the
> > analog TV mode to be used.
> > 
> > However, this was causing multiple issues:
> > 
> >   * The mode name parsed on the command line was passed directly to the
> >     driver, which had to figure out which mode it was suppose to match;
> > 
> >   * Figuring that out wasn't really easy, since the video= argument or what
> >     the userspace might not even have a name in the first place, but
> >     instead could have passed a mode with the same timings;
> > 
> >   * The fallback to matching on the timings was mostly working as long as
> >     we were supporting one 525 lines (most likely NSTC) and one 625 lines
> >     (PAL), but couldn't differentiate between two modes with the same
> >     timings (NTSC vs PAL-M vs NSTC-J for example);
> > 
> >   * There was also some overlap with the tv mode property registered by
> >     drm_mode_create_tv_properties(), but named modes weren't interacting
> >     with that property at all.
> > 
> >   * Even though that property was generic, its possible values were
> >     specific to each drivers, which made some generic support difficult.
> > 
> > Thus, I chose to tackle in multiple steps:
> > 
> >   * A new TV mode property was introduced, with generic values, each driver
> >     reporting through a bitmask what standard it supports to the userspace;
> > 
> >   * This option was added to the command line parsing code to be able to
> >     specify it on the kernel command line, and new atomic_check and reset
> >     helpers were created to integrate properly into atomic KMS;
> > 
> >   * The named mode parsing code is now creating a proper display mode for
> >     the given named mode, and the TV standard will thus be part of the
> >     connector state;
> > 
> >   * Two drivers were converted and tested for now (vc4 and sun4i), with
> >     some backward compatibility code to translate the old TV mode to the
> >     new TV mode;
> > 
> > Unit tests were created along the way.
> > 
> > One can switch from NTSC to PAL now using (on vc4)
> > 
> > modetest -M vc4  -s 53:720x480i -w 53:'TV mode':1 # NTSC
> > modetest -M vc4  -s 53:720x576i -w 53:'TV mode':4 # PAL
> > 
> > Let me know what you think,
> > Maxime
> > 
> 
> I suggest that you apply the patches that are reviewed, have merrit on
> their own and are not tied to the TV mode property.
> This will help in keeping this rather big patchset focused and ease the
> task for reviewers.
> 
> The following seems to be in that group:
> 
>   drm/tests: Order Kunit tests in Makefile
>   drm/atomic-helper: Rename drm_atomic_helper_connector_tv_reset to
> avoid ambiguity
>   drm/connector: Rename subconnector state variable
>   drm/atomic: Add TV subconnector property to get/set_property
>   drm/modes: Only consider bpp and refresh before options
>   drm/modes: parse_cmdline: Add support for named modes containing dashes
>   drm/vc4: vec: Fix definition of PAL-M mode

Yeah, that was my intention with this series, it's done now, thanks for the reminder :)

Maxime

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Re: [PATCH v4 14/30] drm/client: Add some tests for drm_connector_pick_cmdline_mode()

[Maíra Canal]

On 9/29/22 13:31, Maxime Ripard wrote:
> drm_connector_pick_cmdline_mode() is in charge of finding a proper
> drm_display_mode from the definition we got in the video= command line
> argument.
> 
> Let's add some unit tests to make sure we're not getting any regressions
> there.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 
> ---
> Changes in v4:
> - Removed MODULE macros
> ---
>  drivers/gpu/drm/drm_client_modeset.c            |   4 +
>  drivers/gpu/drm/tests/drm_client_modeset_test.c | 105 ++++++++++++++++++++++++
>  2 files changed, 109 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
> index bbc535cc50dd..d553e793e673 100644
> --- a/drivers/gpu/drm/drm_client_modeset.c
> +++ b/drivers/gpu/drm/drm_client_modeset.c
> @@ -1237,3 +1237,7 @@ int drm_client_modeset_dpms(struct drm_client_dev *client, int mode)
>  	return ret;
>  }
>  EXPORT_SYMBOL(drm_client_modeset_dpms);
> +
> +#ifdef CONFIG_DRM_KUNIT_TEST
> +#include "tests/drm_client_modeset_test.c"
> +#endif
> diff --git a/drivers/gpu/drm/tests/drm_client_modeset_test.c b/drivers/gpu/drm/tests/drm_client_modeset_test.c
> new file mode 100644
> index 000000000000..09dc5acbbc42
> --- /dev/null
> +++ b/drivers/gpu/drm/tests/drm_client_modeset_test.c
> @@ -0,0 +1,105 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2022 Maxime Ripard <mripard@kernel.org>
> + */
> +
> +#include <kunit/test.h>
> +
> +#include <drm/drm_connector.h>
> +#include <drm/drm_edid.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_modeset_helper_vtables.h>
> +#include <drm/drm_probe_helper.h>
> +
> +#include "drm_kunit_helpers.h"
> +
> +struct drm_client_modeset_test_priv {
> +	struct drm_device *drm;
> +	struct drm_connector connector;
> +};
> +
> +static int drm_client_modeset_connector_get_modes(struct drm_connector *connector)
> +{
> +	struct drm_display_mode *mode;

Small nit: I guess this should be added on patch 21/30, as it is not
being currently used.

> +	int count;
> +
> +	count = drm_add_modes_noedid(connector, 1920, 1200);
> +
> +	return count;
> +}
> +
> +static const struct drm_connector_helper_funcs drm_client_modeset_connector_helper_funcs = {
> +	.get_modes = drm_client_modeset_connector_get_modes,
> +};
> +
> +static const struct drm_connector_funcs drm_client_modeset_connector_funcs = {
> +};
> +
> +static int drm_client_modeset_test_init(struct kunit *test)
> +{
> +	struct drm_client_modeset_test_priv *priv;
> +	int ret;
> +
> +	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;

I believe it would be nicer to use KUNIT_ASSERT_NOT_NULL here, instead
of returning a error.

> +	test->priv = priv;
> +
> +	priv->drm = drm_kunit_device_init(test, "drm-client-modeset-test");
> +	if (IS_ERR(priv->drm))
> +		return PTR_ERR(priv->drm);

Here you could use KUNIT_ASSERT_NOT_ERR_OR_NULL.

> +
> +	ret = drmm_connector_init(priv->drm, &priv->connector,
> +				  &drm_client_modeset_connector_funcs,
> +				  DRM_MODE_CONNECTOR_Unknown,
> +				  NULL);
> +	if (ret)
> +		return ret;

Same idea here. This would make it more compliant to the KUnit API.

> +	drm_connector_helper_add(&priv->connector, &drm_client_modeset_connector_helper_funcs);
> +
> +	return 0;
> +
> +}
> +
> +static void drm_pick_cmdline_res_1920_1080_60(struct kunit *test)
> +{
> +	struct drm_client_modeset_test_priv *priv = test->priv;
> +	struct drm_device *drm = priv->drm;
> +	struct drm_connector *connector = &priv->connector;
> +	struct drm_cmdline_mode *cmdline_mode = &connector->cmdline_mode;
> +	struct drm_display_mode *expected_mode, *mode;
> +	const char *cmdline = "1920x1080@60";
> +	int ret;
> +
> +	expected_mode = drm_mode_find_dmt(priv->drm, 1920, 1080, 60, false);
> +	KUNIT_ASSERT_PTR_NE(test, expected_mode, NULL);

You could use KUNIT_ASSERT_NOT_NULL here.

> +
> +	KUNIT_ASSERT_TRUE(test,
> +			  drm_mode_parse_command_line_for_connector(cmdline,
> +								    connector,
> +								    cmdline_mode));
> +
> +	mutex_lock(&drm->mode_config.mutex);
> +	ret = drm_helper_probe_single_connector_modes(connector, 1920, 1080);
> +	mutex_unlock(&drm->mode_config.mutex);
> +	KUNIT_ASSERT_GT(test, ret, 0);
> +
> +	mode = drm_connector_pick_cmdline_mode(connector);
> +	KUNIT_ASSERT_PTR_NE(test, mode, NULL);

You could also use KUNIT_ASSERT_NOT_NULL here.

This idea could also apply to the patches 21/30 and 22/30, which have a
similar structure and are also using KUNIT_ASSERT_PTR_NE.

Best Regards,
- Maíra Canal

> +
> +	KUNIT_EXPECT_TRUE(test, drm_mode_equal(expected_mode, mode));
> +}
> +
> +static struct kunit_case drm_pick_cmdline_tests[] = {
> +	KUNIT_CASE(drm_pick_cmdline_res_1920_1080_60),
> +	{}
> +};
> +
> +static struct kunit_suite drm_pick_cmdline_test_suite = {
> +	.name = "drm_pick_cmdline",
> +	.init = drm_client_modeset_test_init,
> +	.test_cases = drm_pick_cmdline_tests
> +};
> +
> +kunit_test_suite(drm_pick_cmdline_test_suite);
> 

Re: (subset) [PATCH v4 02/30] drm/tests: Order Kunit tests in Makefile

[Maxime Ripard]

On Thu, 29 Sep 2022 18:30:56 +0200, Maxime Ripard wrote:
> Since we've recently added a ton of tests, the list starts to be a bit
> of a mess and creates unneeded conflicts.
> 
> Let's order it alphabetically.
> 
> 

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime

Re: (subset) [PATCH v4 04/30] drm/atomic-helper: Rename drm_atomic_helper_connector_tv_reset to avoid ambiguity

[Maxime Ripard]

On Thu, 29 Sep 2022 18:30:58 +0200, Maxime Ripard wrote:
> We currently have two sets of TV properties.
> 
> The first one is there to deal with analog TV properties, creating
> properties such as the TV mode, subconnectors, saturation, hue and so on.
> It's created by calling the drm_mode_create_tv_properties() function.
> 
> The second one is there to deal with properties that might be useful on a
> TV, creating the overscan margins for example. It's created by calling the
> drm_mode_create_tv_margin_properties().
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime

Re: (subset) [PATCH v4 05/30] drm/connector: Rename subconnector state variable

[Maxime Ripard]

On Thu, 29 Sep 2022 18:30:59 +0200, Maxime Ripard wrote:
> There is two TV subconnector related properties registered by
> drm_mode_create_tv_properties(): subconnector and select subconnector.
> 
> While the select subconnector property is stored in the kernel by the
> drm_tv_connector_state structure, the subconnector property isn't stored
> anywhere.
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime

Re: (subset) [PATCH v4 06/30] drm/atomic: Add TV subconnector property to get/set_property

[Maxime Ripard]

On Thu, 29 Sep 2022 18:31:00 +0200, Maxime Ripard wrote:
> The subconnector property was created by drm_mode_create_tv_properties(),
> but wasn't exposed to the userspace through the generic
> atomic_get/set_property implementation, and wasn't stored in any generic
> state structure.
> 
> Let's solve this.
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime

Re: (subset) [PATCH v4 12/30] drm/modes: Only consider bpp and refresh before options

[Maxime Ripard]

On Thu, 29 Sep 2022 18:31:06 +0200, Maxime Ripard wrote:
> Some video= options might have a value that contains a dash. However, the
> command line parsing mode considers all dashes as the separator between the
> mode and the bpp count.
> 
> Let's rework the parsing code a bit to only consider a dash as the bpp
> separator if it before a comma, the options separator.
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime

Re: (subset) [PATCH v4 13/30] drm/modes: parse_cmdline: Add support for named modes containing dashes

[Maxime Ripard]

On Thu, 29 Sep 2022 18:31:07 +0200, Maxime Ripard wrote:
> From: Geert Uytterhoeven <geert@linux-m68k.org>
> 
> It is fairly common for named video modes to contain dashes (e.g.
> "tt-mid" on Atari, "dblntsc-ff" on Amiga).  Currently such mode names
> are not recognized, as the dash is considered to be a separator between
> mode name and bpp.
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime

Re: (subset) [PATCH v4 25/30] drm/vc4: vec: Fix definition of PAL-M mode

[Maxime Ripard]

On Thu, 29 Sep 2022 18:31:19 +0200, Maxime Ripard wrote:
> From: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
> 
> PAL-M is a Brazilian analog TV standard that uses a PAL-style chroma
> subcarrier at 3.575611[888111] MHz on top of 525-line (480i60) timings.
> This commit makes the driver actually use the proper VEC preset for this
> mode instead of just changing PAL subcarrier frequency.
> 
> [...]

Applied to drm/drm-misc (drm-misc-next).

Thanks!
Maxime