Re: [PATCH] RFC: Introduce FW_INFO* functions

[Joe Perches <joe@perches.com>]

On Fri, 2013-09-27 at 09:22 -0400, Prarit Bhargava wrote:
> I'm proposing with this patch to do something similar to the WARN()
> mechanism that is currently implemented in the kernel.  This
> patchset introduces FW_INFO() and FW_INFO_DEV() which logs output

My first thought was "how ugly".
There must be a better way than scraping dmesg output.

> diff --git a/kernel/panic.c b/kernel/panic.c
[]
> @@ -445,6 +446,29 @@ void warn_slowpath_fmt_taint(const char *file, int line,
>  }
>  EXPORT_SYMBOL(warn_slowpath_fmt_taint);
>  
> +void warn_slowpath_fmt_dev(const char *file, int line,
> +			   struct device *dev, const char *fmt, ...)
> +{
> +	struct slowpath_args args;
> +
> +	pr_info("[Firmware Info]: ");
> +	if (dev)
> +		pr_cont("%s %s: ",
> +			dev_driver_string(dev), dev_name(dev));
> +	pr_cont("at %s:%d ", file, line);
> +
> +	args.fmt = fmt;
> +	va_start(args.args, fmt);
> +	vprintk(args.fmt, args.args);
> +	va_end(args.args);
> +	if (dump_hardware_arch_desc())
> +		pr_info("[Firmware Info]: %s\n", dump_hardware_arch_desc());
> +	else
> +		pr_info("[Firmware Info]: Hardware Unidentified\n");
> +}
> +EXPORT_SYMBOL(warn_slowpath_fmt_dev);

This bit should just use %pV and a single printk to
avoid any possible message interleaving.

{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt)

	vaf.fmt = fmt;
	vaf.va = &args;

	if (dev)
		pr_info("[Firmware Info]: %s %s at %s:%d %pV",
			dev_driver_string(dev), dev_name(dev),
			file, line, &vaf);
	else
		pr_info("[Firmware Info]: at %s:%d %pV",
			file, line, &vaf);

	etc...