On Fri, 17 May 2024, Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx> wrote:
> We already have some drm printk functions that need to duplicate
> a code to get a similar format of the final result, for example:
>
> [ ] 0000:00:00.0: [drm:foo] bar
> [ ] 0000:00:00.0: [drm] foo bar
> [ ] 0000:00:00.0: [drm] *ERROR* foo
>
> Add a generic __drm_dev_vprintk() function that can format the
> final message like all other existing function do and allows us
> to keep the formatting code in one place.
Nice idea!
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
> drivers/gpu/drm/drm_print.c | 49 ++++++++++++++++++++-----------------
> include/drm/drm_print.h | 3 +++
> 2 files changed, 30 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
> index cf2efb44722c..a2b60c8245a1 100644
> --- a/drivers/gpu/drm/drm_print.c
> +++ b/drivers/gpu/drm/drm_print.c
> @@ -187,19 +187,12 @@ void __drm_printfn_dbg(struct drm_printer *p, struct va_format *vaf)
> const struct drm_device *drm = p->arg;
> const struct device *dev = drm ? drm->dev : NULL;
> enum drm_debug_category category = p->category;
> - const char *prefix = p->prefix ?: "";
> - const char *prefix_pad = p->prefix ? " " : "";
>
> if (!__drm_debug_enabled(category))
> return;
>
> /* Note: __builtin_return_address(0) is useless here. */
> - if (dev)
> - dev_printk(KERN_DEBUG, dev, "[" DRM_NAME "]%s%s %pV",
> - prefix_pad, prefix, vaf);
> - else
> - printk(KERN_DEBUG "[" DRM_NAME "]%s%s %pV",
> - prefix_pad, prefix, vaf);
> + __drm_dev_vprintk(dev, KERN_DEBUG, NULL, p->prefix, vaf);
> }
> EXPORT_SYMBOL(__drm_printfn_dbg);
>
> @@ -277,6 +270,29 @@ void drm_print_bits(struct drm_printer *p, unsigned long value,
> }
> EXPORT_SYMBOL(drm_print_bits);
>
> +void __drm_dev_vprintk(const struct device *dev, const char *level,
> + const void *origin, const char *prefix,
> + struct va_format *vaf)
> +{
> + const char *prefix_pad = prefix ? " " : (prefix = "");
Too clever, please just keep it simple:
const char *prefix_pad = prefix ? " " : "";
if (!prefix)
prefix = "";
> +
> + if (dev)
> + if (origin)
> + dev_printk(level, dev, "[" DRM_NAME ":%ps]%s%s %pV",
> + origin, prefix_pad, prefix, vaf);
> + else
> + dev_printk(level, dev, "[" DRM_NAME "]%s%s %pV",
> + prefix_pad, prefix, vaf);
> + else
> + if (origin)
> + printk("%s" "[" DRM_NAME ":%ps]%s%s %pV",
> + level, origin, prefix_pad, prefix, vaf);
> + else
> + printk("%s" "[" DRM_NAME "]%s%s %pV",
> + level, prefix_pad, prefix, vaf);
I'd sprinkle a few curly braces around the top level if-else blocks.
Side note, feels like using DRM_NAME makes things harder, not
easier. But that's for another patch.
> +}
> +EXPORT_SYMBOL(__drm_dev_vprintk);
AFAICT this could be a non-exported static function. And probably moved
earlier in the file to not require a declaration.
BR,
Jani.
> +
> void drm_dev_printk(const struct device *dev, const char *level,
> const char *format, ...)
> {
> @@ -287,12 +303,7 @@ void drm_dev_printk(const struct device *dev, const char *level,
> vaf.fmt = format;
> vaf.va = &args;
>
> - if (dev)
> - dev_printk(level, dev, "[" DRM_NAME ":%ps] %pV",
> - __builtin_return_address(0), &vaf);
> - else
> - printk("%s" "[" DRM_NAME ":%ps] %pV",
> - level, __builtin_return_address(0), &vaf);
> + __drm_dev_vprintk(dev, level, __builtin_return_address(0), NULL, &vaf);
>
> va_end(args);
> }
> @@ -312,12 +323,7 @@ void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
> vaf.fmt = format;
> vaf.va = &args;
>
> - if (dev)
> - dev_printk(KERN_DEBUG, dev, "[" DRM_NAME ":%ps] %pV",
> - __builtin_return_address(0), &vaf);
> - else
> - printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV",
> - __builtin_return_address(0), &vaf);
> + __drm_dev_vprintk(dev, KERN_DEBUG, __builtin_return_address(0), NULL, &vaf);
>
> va_end(args);
> }
> @@ -351,8 +357,7 @@ void __drm_err(const char *format, ...)
> vaf.fmt = format;
> vaf.va = &args;
>
> - printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
> - __builtin_return_address(0), &vaf);
> + __drm_dev_vprintk(NULL, KERN_ERR, __builtin_return_address(0), "*ERROR*", &vaf);
>
> va_end(args);
> }
> diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
> index 089950ad8681..bb1801c58544 100644
> --- a/include/drm/drm_print.h
> +++ b/include/drm/drm_print.h
> @@ -366,6 +366,9 @@ static inline struct drm_printer drm_err_printer(struct drm_device *drm,
> __printf(3, 4)
> void drm_dev_printk(const struct device *dev, const char *level,
> const char *format, ...);
> +void __drm_dev_vprintk(const struct device *dev, const char *level,
> + const void *origin, const char *prefix,
> + struct va_format *vaf);
> struct _ddebug;
> __printf(4, 5)
> void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
--
Jani Nikula, Intel
