Re: [PATCH 04/10] drm/print: Fix support for NULL as first argument of drm_dbg_*

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 21 Dec 2022, Siddh Raman Pant <code@siddh.me> wrote:
> Comments say macros DRM_DEBUG_* are deprecated in favor of
> drm_dbg_*(NULL, ...), but they have broken support for it,
> as the macro will result in `(NULL) ? (NULL)->dev : NULL`.

What's wrong with that?

>
> Thus, fix them by casting input drm to a temporary struct ptr,
> with the same convention as in __DRM_DEFINE_DBG_RATELIMITED.
>
> Signed-off-by: Siddh Raman Pant <code@siddh.me>
> ---
>  include/drm/drm_print.h | 89 ++++++++++++++++++++++++++++++++---------
>  1 file changed, 69 insertions(+), 20 deletions(-)
>
> diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
> index a44fb7ef257f..53702d830291 100644
> --- a/include/drm/drm_print.h
> +++ b/include/drm/drm_print.h
> @@ -486,26 +486,75 @@ void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
>  	__drm_printk((drm), err, _ratelimited, "*ERROR* " fmt, ##__VA_ARGS__)
>  
>  
> -#define drm_dbg_core(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_CORE, fmt, ##__VA_ARGS__)
> -#define drm_dbg_driver(drm, fmt, ...)						\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
> -#define drm_dbg_kms(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_KMS, fmt, ##__VA_ARGS__)
> -#define drm_dbg_prime(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_PRIME, fmt, ##__VA_ARGS__)
> -#define drm_dbg_atomic(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_ATOMIC, fmt, ##__VA_ARGS__)
> -#define drm_dbg_vbl(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_VBL, fmt, ##__VA_ARGS__)
> -#define drm_dbg_state(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_STATE, fmt, ##__VA_ARGS__)
> -#define drm_dbg_lease(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_LEASE, fmt, ##__VA_ARGS__)
> -#define drm_dbg_dp(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DP, fmt, ##__VA_ARGS__)
> -#define drm_dbg_drmres(drm, fmt, ...)					\
> -	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRMRES, fmt, ##__VA_ARGS__)
> +#define drm_dbg_core(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_CORE,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_driver(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_DRIVER,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_kms(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_KMS,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_prime(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_PRIME,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_atomic(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_ATOMIC,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_vbl(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_VBL,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_state(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_STATE,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_lease(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_LEASE,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_dp(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_DP,		\
> +		    fmt, ##__VA_ARGS__);			\
> +})
> +
> +#define drm_dbg_drmres(drm, fmt, ...)				\
> +({								\
> +	const struct drm_device *drm_ = (drm);			\
> +	drm_dev_dbg(drm_ ? drm_->dev : NULL, DRM_UT_DRMRES,	\
> +		    fmt, ##__VA_ARGS__);			\
> +})
>  
>  #define drm_dbg(drm, fmt, ...)	drm_dbg_driver(drm, fmt, ##__VA_ARGS__)

-- 
Jani Nikula, Intel Open Source Graphics Center