[PATCH 07/10] drm/i915/display: identify display steppings in display probe

Matt Roper matthew.d.roper at intel.com
Tue Aug 20 23:52:45 UTC 2024


On Tue, Aug 20, 2024 at 10:00:40PM +0300, Jani Nikula wrote:
> Both i915 and xe have code to identify display steppings. Start
> deduplicating this by, uh, adding a third copy in display code. This is
> not yet used for anything other than debug logging. We'll switch over
> later.
> 
> For platforms before GMD ID, attach the mapping from PCI revision to
> stepping in the platform and subplatform descriptors. This is a
> considerably cleaner approach than having it completely separate.
> 
> Also add a separate field for stepping in display runtime info,
> preserving the value from GMD ID.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  .../drm/i915/display/intel_display_device.c   | 224 +++++++++++++++++-
>  .../drm/i915/display/intel_display_device.h   |   3 +-
>  .../drm/xe/compat-i915-headers/intel_step.h   |   1 +
>  3 files changed, 216 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index a31f89df2c0a..1ac3ab3954a1 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -16,14 +16,25 @@
>  #include "intel_display_power.h"
>  #include "intel_display_reg_defs.h"
>  #include "intel_fbc.h"
> +#include "intel_step.h"
>  
>  __diag_push();
>  __diag_ignore_all("-Woverride-init", "Allow field initialization overrides for display info");
>  
> +struct stepping_desc {
> +	const enum intel_step *map; /* revid to step map */
> +	size_t size; /* map size */
> +};
> +
> +#define STEP_INFO(_map)				\
> +	.step_info.map = _map,			\
> +	.step_info.size = ARRAY_SIZE(_map)
> +
>  struct subplatform_desc {
>  	enum intel_display_subplatform subplatform;
>  	const char *name;
>  	const u16 *pciidlist;
> +	struct stepping_desc step_info;
>  };
>  
>  struct platform_desc {
> @@ -31,6 +42,7 @@ struct platform_desc {
>  	const char *name;
>  	const struct subplatform_desc *subplatforms;
>  	const struct intel_display_device_info *info; /* NULL for GMD ID */
> +	struct stepping_desc step_info;
>  };
>  
>  #define PLATFORM(_platform)			 \
> @@ -610,6 +622,13 @@ static const u16 skl_ulx_ids[] = {
>  	0
>  };
>  
> +static const enum intel_step skl_steppings[] = {
> +	[0x6] = STEP_G0,
> +	[0x7] = STEP_H0,
> +	[0x9] = STEP_J0,
> +	[0xA] = STEP_I1,
> +};
> +
>  static const struct platform_desc skl_desc = {
>  	PLATFORM(SKYLAKE),
>  	.subplatforms = (const struct subplatform_desc[]) {
> @@ -618,6 +637,7 @@ static const struct platform_desc skl_desc = {
>  		{},
>  	},
>  	.info = &skl_display,
> +	STEP_INFO(skl_steppings),
>  };
>  
>  static const u16 kbl_ult_ids[] = {
> @@ -634,6 +654,16 @@ static const u16 kbl_ulx_ids[] = {
>  	0
>  };
>  
> +static const enum intel_step kbl_steppings[] = {
> +	[1] = STEP_B0,
> +	[2] = STEP_B0,
> +	[3] = STEP_B0,
> +	[4] = STEP_C0,
> +	[5] = STEP_B1,
> +	[6] = STEP_B1,
> +	[7] = STEP_C0,
> +};
> +
>  static const struct platform_desc kbl_desc = {
>  	PLATFORM(KABYLAKE),
>  	.subplatforms = (const struct subplatform_desc[]) {
> @@ -642,6 +672,7 @@ static const struct platform_desc kbl_desc = {
>  		{},
>  	},
>  	.info = &skl_display,
> +	STEP_INFO(kbl_steppings),
>  };
>  
>  static const u16 cfl_ult_ids[] = {
> @@ -706,6 +737,13 @@ static const struct platform_desc cml_desc = {
>  		BIT(TRANSCODER_DSI_A) | BIT(TRANSCODER_DSI_C), \
>  	.__runtime_defaults.port_mask = BIT(PORT_A) | BIT(PORT_B) | BIT(PORT_C)
>  
> +static const enum intel_step bxt_steppings[] = {
> +	[0xA] = STEP_C0,
> +	[0xB] = STEP_C0,
> +	[0xC] = STEP_D0,
> +	[0xD] = STEP_E0,
> +};
> +
>  static const struct platform_desc bxt_desc = {
>  	PLATFORM(BROXTON),
>  	.info = &(const struct intel_display_device_info) {
> @@ -714,6 +752,11 @@ static const struct platform_desc bxt_desc = {
>  
>  		.__runtime_defaults.ip.ver = 9,
>  	},
> +	STEP_INFO(bxt_steppings),
> +};
> +
> +static const enum intel_step glk_steppings[] = {
> +	[3] = STEP_B0,
>  };
>  
>  static const struct platform_desc glk_desc = {
> @@ -725,6 +768,7 @@ static const struct platform_desc glk_desc = {
>  
>  		.__runtime_defaults.ip.ver = 10,
>  	},
> +	STEP_INFO(glk_steppings),
>  };
>  
>  #define ICL_DISPLAY \
> @@ -773,6 +817,10 @@ static const u16 icl_port_f_ids[] = {
>  	0
>  };
>  
> +static const enum intel_step icl_steppings[] = {
> +	[7] = STEP_D0,
> +};
> +
>  static const struct platform_desc icl_desc = {
>  	PLATFORM(ICELAKE),
>  	.subplatforms = (const struct subplatform_desc[]) {
> @@ -784,6 +832,7 @@ static const struct platform_desc icl_desc = {
>  
>  		.__runtime_defaults.port_mask = BIT(PORT_A) | BIT(PORT_B) | BIT(PORT_C) | BIT(PORT_D) | BIT(PORT_E),
>  	},
> +	STEP_INFO(icl_steppings),
>  };
>  
>  static const struct intel_display_device_info jsl_ehl_display = {
> @@ -792,14 +841,21 @@ static const struct intel_display_device_info jsl_ehl_display = {
>  	.__runtime_defaults.port_mask = BIT(PORT_A) | BIT(PORT_B) | BIT(PORT_C) | BIT(PORT_D),
>  };
>  
> +static const enum intel_step jsl_ehl_steppings[] = {
> +	[0] = STEP_A0,
> +	[1] = STEP_B0,
> +};
> +
>  static const struct platform_desc jsl_desc = {
>  	PLATFORM(JASPERLAKE),
>  	.info = &jsl_ehl_display,
> +	STEP_INFO(jsl_ehl_steppings),
>  };
>  
>  static const struct platform_desc ehl_desc = {
>  	PLATFORM(ELKHARTLAKE),
>  	.info = &jsl_ehl_display,
> +	STEP_INFO(jsl_ehl_steppings),
>  };
>  
>  #define XE_D_DISPLAY \
> @@ -850,10 +906,23 @@ static const u16 tgl_uy_ids[] = {
>  	0
>  };
>  
> +static const enum intel_step tgl_steppings[] = {
> +	[0] = STEP_B0,
> +	[1] = STEP_D0,
> +};
> +
> +static const enum intel_step tgl_uy_steppings[] = {
> +	[0] = STEP_A0,
> +	[1] = STEP_C0,
> +	[2] = STEP_C0,
> +	[3] = STEP_D0,
> +};
> +
>  static const struct platform_desc tgl_desc = {
>  	PLATFORM(TIGERLAKE),
>  	.subplatforms = (const struct subplatform_desc[]) {
> -		{ INTEL_DISPLAY_TIGERLAKE_UY, "UY", tgl_uy_ids },
> +		{ INTEL_DISPLAY_TIGERLAKE_UY, "UY", tgl_uy_ids,
> +		  STEP_INFO(tgl_uy_steppings) },
>  		{},
>  	},
>  	.info = &(const struct intel_display_device_info) {
> @@ -866,6 +935,12 @@ static const struct platform_desc tgl_desc = {
>  		.__runtime_defaults.port_mask = BIT(PORT_A) | BIT(PORT_B) |
>  		BIT(PORT_TC1) | BIT(PORT_TC2) | BIT(PORT_TC3) | BIT(PORT_TC4) | BIT(PORT_TC5) | BIT(PORT_TC6),
>  	},
> +	STEP_INFO(tgl_steppings),
> +};
> +
> +static const enum intel_step dg1_steppings[] = {
> +	[0] = STEP_A0,
> +	[1] = STEP_B0,
>  };
>  
>  static const struct platform_desc dg1_desc = {
> @@ -876,6 +951,13 @@ static const struct platform_desc dg1_desc = {
>  		.__runtime_defaults.port_mask = BIT(PORT_A) | BIT(PORT_B) |
>  		BIT(PORT_TC1) | BIT(PORT_TC2),
>  	},
> +	STEP_INFO(dg1_steppings),
> +};
> +
> +static const enum intel_step rkl_steppings[] = {
> +	[0] = STEP_A0,
> +	[1] = STEP_B0,
> +	[4] = STEP_C0,
>  };
>  
>  static const struct platform_desc rkl_desc = {
> @@ -892,6 +974,7 @@ static const struct platform_desc rkl_desc = {
>  		.__runtime_defaults.port_mask = BIT(PORT_A) | BIT(PORT_B) |
>  		BIT(PORT_TC1) | BIT(PORT_TC2),
>  	},
> +	STEP_INFO(rkl_steppings),
>  };
>  
>  static const u16 adls_rpls_ids[] = {
> @@ -899,10 +982,24 @@ static const u16 adls_rpls_ids[] = {
>  	0
>  };
>  
> +static const enum intel_step adl_s_steppings[] = {
> +	[0x0] = STEP_A0,
> +	[0x1] = STEP_A2,
> +	[0x4] = STEP_B0,
> +	[0x8] = STEP_B0,
> +	[0xC] = STEP_C0,
> +};
> +
> +static const enum intel_step adl_s_rpl_s_steppings[] = {
> +	[0x4] = STEP_D0,
> +	[0xC] = STEP_C0,
> +};
> +
>  static const struct platform_desc adl_s_desc = {
>  	PLATFORM(ALDERLAKE_S),
>  	.subplatforms = (const struct subplatform_desc[]) {
> -		{ INTEL_DISPLAY_ALDERLAKE_S_RAPTORLAKE_S, "RPL-S", adls_rpls_ids },
> +		{ INTEL_DISPLAY_ALDERLAKE_S_RAPTORLAKE_S, "RPL-S", adls_rpls_ids,
> +		  STEP_INFO(adl_s_rpl_s_steppings) },
>  		{},
>  	},
>  	.info = &(const struct intel_display_device_info) {
> @@ -913,6 +1010,7 @@ static const struct platform_desc adl_s_desc = {
>  		.__runtime_defaults.port_mask = BIT(PORT_A) |
>  		BIT(PORT_TC1) | BIT(PORT_TC2) | BIT(PORT_TC3) | BIT(PORT_TC4),
>  	},
> +	STEP_INFO(adl_s_steppings),
>  };
>  
>  #define XE_LPD_FEATURES \
> @@ -986,15 +1084,34 @@ static const u16 adlp_rplp_ids[] = {
>  	0
>  };
>  
> +static const enum intel_step adl_p_steppings[] = {
> +	[0x0] = STEP_A0,
> +	[0x4] = STEP_B0,
> +	[0x8] = STEP_C0,
> +	[0xC] = STEP_D0,
> +};
> +
> +static const enum intel_step adl_p_adl_n_steppings[] = {
> +	[0x0] = STEP_D0,
> +};
> +
> +static const enum intel_step adl_p_rpl_pu_steppings[] = {
> +	[0x4] = STEP_E0,
> +};
> +
>  static const struct platform_desc adl_p_desc = {
>  	PLATFORM(ALDERLAKE_P),
>  	.subplatforms = (const struct subplatform_desc[]) {
> -		{ INTEL_DISPLAY_ALDERLAKE_P_ALDERLAKE_N, "ADL-N", adlp_adln_ids },
> -		{ INTEL_DISPLAY_ALDERLAKE_P_RAPTORLAKE_U, "RPL-U", adlp_rplu_ids },
> -		{ INTEL_DISPLAY_ALDERLAKE_P_RAPTORLAKE_P, "RPL-P", adlp_rplp_ids },
> +		{ INTEL_DISPLAY_ALDERLAKE_P_ALDERLAKE_N, "ADL-N", adlp_adln_ids,
> +		  STEP_INFO(adl_p_adl_n_steppings) },
> +		{ INTEL_DISPLAY_ALDERLAKE_P_RAPTORLAKE_P, "RPL-P", adlp_rplp_ids,
> +		  STEP_INFO(adl_p_rpl_pu_steppings) },
> +		{ INTEL_DISPLAY_ALDERLAKE_P_RAPTORLAKE_U, "RPL-U", adlp_rplu_ids,
> +		  STEP_INFO(adl_p_rpl_pu_steppings) },
>  		{},
>  	},
>  	.info = &xe_lpd_display,
> +	STEP_INFO(adl_p_steppings),
>  };
>  
>  static const struct intel_display_device_info xe_hpd_display = {
> @@ -1023,12 +1140,33 @@ static const u16 dg2_g12_ids[] = {
>  	0
>  };
>  
> +static const enum intel_step dg2_g10_steppings[] = {
> +	[0x0] = STEP_A0,
> +	[0x1] = STEP_A0,
> +	[0x4] = STEP_B0,
> +	[0x8] = STEP_C0,
> +};
> +
> +static const enum intel_step dg2_g11_steppings[] = {
> +	[0x0] = STEP_B0,
> +	[0x4] = STEP_C0,
> +	[0x5] = STEP_C0,
> +};
> +
> +static const enum intel_step dg2_g12_steppings[] = {
> +	[0x0] = STEP_C0,
> +	[0x1] = STEP_C0,
> +};
> +
>  static const struct platform_desc dg2_desc = {
>  	PLATFORM(DG2),
>  	.subplatforms = (const struct subplatform_desc[]) {
> -		{ INTEL_DISPLAY_DG2_G10, "G10", dg2_g10_ids },
> -		{ INTEL_DISPLAY_DG2_G11, "G11", dg2_g11_ids },
> -		{ INTEL_DISPLAY_DG2_G12, "G12", dg2_g12_ids },
> +		{ INTEL_DISPLAY_DG2_G10, "G10", dg2_g10_ids,
> +		  STEP_INFO(dg2_g10_steppings) },
> +		{ INTEL_DISPLAY_DG2_G11, "G11", dg2_g11_ids,
> +		  STEP_INFO(dg2_g11_steppings) },
> +		{ INTEL_DISPLAY_DG2_G12, "G12", dg2_g12_ids,
> +		  STEP_INFO(dg2_g12_steppings) },
>  		{},
>  	},
>  	.info = &xe_hpd_display,
> @@ -1261,13 +1399,66 @@ find_subplatform_desc(struct pci_dev *pdev, const struct platform_desc *desc)
>  	return NULL;
>  }
>  
> +static enum intel_step get_pre_gmdid_step(struct intel_display *display,
> +					  const struct stepping_desc *main,
> +					  const struct stepping_desc *sub)
> +{
> +	struct pci_dev *pdev = to_pci_dev(display->drm->dev);
> +	const enum intel_step *map = main->map;
> +	int size = main->size;
> +	int revision = pdev->revision;
> +	enum intel_step step;
> +
> +	/* subplatform stepping info trumps main platform info */
> +	if (sub->map && sub->size) {
> +		map = sub->map;
> +		size = sub->size;
> +	}
> +
> +	/* not all platforms define steppings, and it's fine */
> +	if (!map || !size)
> +		return STEP_NONE;
> +
> +	if (revision < size && map[revision] != STEP_NONE) {
> +		step = map[revision];
> +	} else {
> +		drm_warn(display->drm, "Unknown revision 0x%02x\n", revision);
> +
> +		/*
> +		 * If we hit a gap in the revision to step map, use the information
> +		 * for the next revision.
> +		 *
> +		 * This may be wrong in all sorts of ways, especially if the
> +		 * steppings in the array are not monotonically increasing, but
> +		 * it's better than defaulting to 0.
> +		 */
> +		while (revision < size && map[revision] == STEP_NONE)
> +			revision++;
> +
> +		if (revision < size) {
> +			drm_dbg_kms(display->drm, "Using display stepping for revision 0x%02x\n",
> +				    revision);
> +			step = map[revision];
> +		} else {
> +			drm_dbg_kms(display->drm, "Using future display stepping\n");
> +			step = STEP_FUTURE;
> +		}
> +	}
> +
> +	drm_WARN_ON(display->drm, step == STEP_NONE);
> +
> +	return step;
> +}
> +
>  void intel_display_device_probe(struct drm_i915_private *i915)
>  {
> +	struct intel_display *display = &i915->display;
>  	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>  	const struct intel_display_device_info *info;
>  	struct intel_display_ip_ver ip_ver = {};
>  	const struct platform_desc *desc;
>  	const struct subplatform_desc *subdesc;
> +	enum intel_step step;
>  
>  	/* Add drm device backpointer as early as possible. */
>  	i915->display.drm = &i915->drm;
> @@ -1307,13 +1498,24 @@ void intel_display_device_probe(struct drm_i915_private *i915)
>  		DISPLAY_RUNTIME_INFO(i915)->subplatform = subdesc->subplatform;
>  	}
>  
> -	if (ip_ver.ver || ip_ver.rel || ip_ver.step)
> +	if (ip_ver.ver || ip_ver.rel || ip_ver.step) {
>  		DISPLAY_RUNTIME_INFO(i915)->ip = ip_ver;
> +		step = STEP_A0 + ip_ver.step;
> +		if (step > STEP_FUTURE) {
> +			drm_dbg_kms(display->drm, "Using future display stepping\n");
> +			step = STEP_FUTURE;
> +		}
> +	} else {
> +		step = get_pre_gmdid_step(display, &desc->step_info, &subdesc->step_info);

Can't subdesc still be NULL here?  And if we change this to something
like "subdesc ? &subdesc->step_info : NULL" then we'll also need a
nullcheck inside get_pre_gmdid_step as well to prevent a npd.


Matt

> +	}
> +
> +	DISPLAY_RUNTIME_INFO(i915)->step = step;
>  
> -	drm_info(&i915->drm, "Found %s%s%s (device ID %04x) display version %u.%02u\n",
> +	drm_info(&i915->drm, "Found %s%s%s (device ID %04x) display version %u.%02u stepping %s\n",
>  		 desc->name, subdesc ? "/" : "", subdesc ? subdesc->name : "",
>  		 pdev->device, DISPLAY_RUNTIME_INFO(i915)->ip.ver,
> -		 DISPLAY_RUNTIME_INFO(i915)->ip.rel);
> +		 DISPLAY_RUNTIME_INFO(i915)->ip.rel,
> +		 step != STEP_NONE ? intel_step_name(step) : "N/A");
>  
>  	return;
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
> index 8bd342658291..1c75cbd68dea 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
> @@ -201,8 +201,9 @@ struct intel_display_runtime_info {
>  	struct intel_display_ip_ver {
>  		u16 ver;
>  		u16 rel;
> -		u16 step;
> +		u16 step; /* hardware */
>  	} ip;
> +	int step; /* symbolic */
>  
>  	u8 pipe_mask;
>  	u8 cpu_transcoder_mask;
> diff --git a/drivers/gpu/drm/xe/compat-i915-headers/intel_step.h b/drivers/gpu/drm/xe/compat-i915-headers/intel_step.h
> index ee3f45b668b9..2cf13a572ab0 100644
> --- a/drivers/gpu/drm/xe/compat-i915-headers/intel_step.h
> +++ b/drivers/gpu/drm/xe/compat-i915-headers/intel_step.h
> @@ -8,6 +8,7 @@
>  
>  #include "xe_step.h"
>  
> +#define intel_step xe_step
>  #define intel_step_name xe_step_name
>  
>  #endif /* __INTEL_STEP_H__ */
> -- 
> 2.39.2
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation


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