Re: [Intel-gfx] [PATCH v3 1/2] drm/i915/dmc: Do not require specific versions

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Thu, Dec 29, 2022 at 04:07:39PM -0300, Gustavo Sousa wrote:
> Currently there is no DMC version requirement with respect to how i915
> interacts with it and new versions of the firmware serve as drop-in
> replacements of older ones. As such, do not require specific versions.
> 
> References: https://lore.kernel.org/r/Y3081s7c5ksutpMW@intel.com

I don't believe this link is a good reference as justification
of this patch.

Probably https://docs.kernel.org/next/driver-api/firmware/firmware-usage-guidelines.html
is a better link?

Also, in the commit message we should be more clear that i915
interacts with the Hardware and not with any FW ABI/API, so the API
is fixed within the platform, hence no need to get this so-tied
version requirement.

with the commit msg changed you can count on my reviewed-by,
the patch looks good to me.

> Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dmc.c | 35 ------------------------
>  drivers/gpu/drm/i915/display/intel_dmc.h |  1 -
>  2 files changed, 36 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
> index 905b5dcdca14..4124b3d37110 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc.c
> +++ b/drivers/gpu/drm/i915/display/intel_dmc.c
> @@ -53,51 +53,40 @@
>  #define DISPLAY_VER12_DMC_MAX_FW_SIZE	ICL_DMC_MAX_FW_SIZE
>  
>  #define DG2_DMC_PATH			DMC_PATH(dg2, 2, 08)
> -#define DG2_DMC_VERSION_REQUIRED	DMC_VERSION(2, 8)
>  MODULE_FIRMWARE(DG2_DMC_PATH);
>  
>  #define ADLP_DMC_PATH			DMC_PATH(adlp, 2, 16)
> -#define ADLP_DMC_VERSION_REQUIRED	DMC_VERSION(2, 16)
>  MODULE_FIRMWARE(ADLP_DMC_PATH);
>  
>  #define ADLS_DMC_PATH			DMC_PATH(adls, 2, 01)
> -#define ADLS_DMC_VERSION_REQUIRED	DMC_VERSION(2, 1)
>  MODULE_FIRMWARE(ADLS_DMC_PATH);
>  
>  #define DG1_DMC_PATH			DMC_PATH(dg1, 2, 02)
> -#define DG1_DMC_VERSION_REQUIRED	DMC_VERSION(2, 2)
>  MODULE_FIRMWARE(DG1_DMC_PATH);
>  
>  #define RKL_DMC_PATH			DMC_PATH(rkl, 2, 03)
> -#define RKL_DMC_VERSION_REQUIRED	DMC_VERSION(2, 3)
>  MODULE_FIRMWARE(RKL_DMC_PATH);
>  
>  #define TGL_DMC_PATH			DMC_PATH(tgl, 2, 12)
> -#define TGL_DMC_VERSION_REQUIRED	DMC_VERSION(2, 12)
>  MODULE_FIRMWARE(TGL_DMC_PATH);
>  
>  #define ICL_DMC_PATH			DMC_PATH(icl, 1, 09)
> -#define ICL_DMC_VERSION_REQUIRED	DMC_VERSION(1, 9)
>  #define ICL_DMC_MAX_FW_SIZE		0x6000
>  MODULE_FIRMWARE(ICL_DMC_PATH);
>  
>  #define GLK_DMC_PATH			DMC_PATH(glk, 1, 04)
> -#define GLK_DMC_VERSION_REQUIRED	DMC_VERSION(1, 4)
>  #define GLK_DMC_MAX_FW_SIZE		0x4000
>  MODULE_FIRMWARE(GLK_DMC_PATH);
>  
>  #define KBL_DMC_PATH			DMC_PATH(kbl, 1, 04)
> -#define KBL_DMC_VERSION_REQUIRED	DMC_VERSION(1, 4)
>  #define KBL_DMC_MAX_FW_SIZE		BXT_DMC_MAX_FW_SIZE
>  MODULE_FIRMWARE(KBL_DMC_PATH);
>  
>  #define SKL_DMC_PATH			DMC_PATH(skl, 1, 27)
> -#define SKL_DMC_VERSION_REQUIRED	DMC_VERSION(1, 27)
>  #define SKL_DMC_MAX_FW_SIZE		BXT_DMC_MAX_FW_SIZE
>  MODULE_FIRMWARE(SKL_DMC_PATH);
>  
>  #define BXT_DMC_PATH			DMC_PATH(bxt, 1, 07)
> -#define BXT_DMC_VERSION_REQUIRED	DMC_VERSION(1, 7)
>  #define BXT_DMC_MAX_FW_SIZE		0x3000
>  MODULE_FIRMWARE(BXT_DMC_PATH);
>  
> @@ -765,17 +754,6 @@ static u32 parse_dmc_fw_css(struct intel_dmc *dmc,
>  		return 0;
>  	}
>  
> -	if (dmc->required_version &&
> -	    css_header->version != dmc->required_version) {
> -		drm_info(&i915->drm, "Refusing to load DMC firmware v%u.%u,"
> -			 " please use v%u.%u\n",
> -			 DMC_VERSION_MAJOR(css_header->version),
> -			 DMC_VERSION_MINOR(css_header->version),
> -			 DMC_VERSION_MAJOR(dmc->required_version),
> -			 DMC_VERSION_MINOR(dmc->required_version));
> -		return 0;
> -	}
> -
>  	dmc->version = css_header->version;
>  
>  	return sizeof(struct intel_css_header);
> @@ -903,49 +881,38 @@ void intel_dmc_ucode_init(struct drm_i915_private *dev_priv)
>  
>  	if (IS_DG2(dev_priv)) {
>  		dmc->fw_path = DG2_DMC_PATH;
> -		dmc->required_version = DG2_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = DISPLAY_VER13_DMC_MAX_FW_SIZE;
>  	} else if (IS_ALDERLAKE_P(dev_priv)) {
>  		dmc->fw_path = ADLP_DMC_PATH;
> -		dmc->required_version = ADLP_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = DISPLAY_VER13_DMC_MAX_FW_SIZE;
>  	} else if (IS_ALDERLAKE_S(dev_priv)) {
>  		dmc->fw_path = ADLS_DMC_PATH;
> -		dmc->required_version = ADLS_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
>  	} else if (IS_DG1(dev_priv)) {
>  		dmc->fw_path = DG1_DMC_PATH;
> -		dmc->required_version = DG1_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
>  	} else if (IS_ROCKETLAKE(dev_priv)) {
>  		dmc->fw_path = RKL_DMC_PATH;
> -		dmc->required_version = RKL_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
>  	} else if (IS_TIGERLAKE(dev_priv)) {
>  		dmc->fw_path = TGL_DMC_PATH;
> -		dmc->required_version = TGL_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
>  	} else if (DISPLAY_VER(dev_priv) == 11) {
>  		dmc->fw_path = ICL_DMC_PATH;
> -		dmc->required_version = ICL_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = ICL_DMC_MAX_FW_SIZE;
>  	} else if (IS_GEMINILAKE(dev_priv)) {
>  		dmc->fw_path = GLK_DMC_PATH;
> -		dmc->required_version = GLK_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = GLK_DMC_MAX_FW_SIZE;
>  	} else if (IS_KABYLAKE(dev_priv) ||
>  		   IS_COFFEELAKE(dev_priv) ||
>  		   IS_COMETLAKE(dev_priv)) {
>  		dmc->fw_path = KBL_DMC_PATH;
> -		dmc->required_version = KBL_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = KBL_DMC_MAX_FW_SIZE;
>  	} else if (IS_SKYLAKE(dev_priv)) {
>  		dmc->fw_path = SKL_DMC_PATH;
> -		dmc->required_version = SKL_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = SKL_DMC_MAX_FW_SIZE;
>  	} else if (IS_BROXTON(dev_priv)) {
>  		dmc->fw_path = BXT_DMC_PATH;
> -		dmc->required_version = BXT_DMC_VERSION_REQUIRED;
>  		dmc->max_fw_size = BXT_DMC_MAX_FW_SIZE;
>  	}
>  
> @@ -958,8 +925,6 @@ void intel_dmc_ucode_init(struct drm_i915_private *dev_priv)
>  		}
>  
>  		dmc->fw_path = dev_priv->params.dmc_firmware_path;
> -		/* Bypass version check for firmware override. */
> -		dmc->required_version = 0;
>  	}
>  
>  	if (!dmc->fw_path) {
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc.h b/drivers/gpu/drm/i915/display/intel_dmc.h
> index 67e03315ef99..435eab9b016b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc.h
> +++ b/drivers/gpu/drm/i915/display/intel_dmc.h
> @@ -25,7 +25,6 @@ enum {
>  struct intel_dmc {
>  	struct work_struct work;
>  	const char *fw_path;
> -	u32 required_version;
>  	u32 max_fw_size; /* bytes */
>  	u32 version;
>  	struct dmc_fw_info {
> -- 
> 2.39.0
>