Re: [PATCH 1/1] lib: devres: Add error information printing for __devm_ioremap_resource()

From: Geert Uytterhoeven
Date: Mon May 17 2021 - 03:04:49 EST

Hi Zhen,

On Wed, Apr 28, 2021 at 8:33 AM Zhen Lei <thunder.leizhen@xxxxxxxxxx> wrote:
> Ensure that all error handling branches print error information. In this
> way, when this function fails, the upper-layer functions can directly
> return an error code without missing debugging information. Otherwise,
> the error message will be printed redundantly or missing.
> Fixes: 35bd8c07db2c ("devres: keep both device name and resource name in pretty name")
> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

Thanks for your patch, which is now commit 5c3e241f5246445d ("lib:
devres: Add error information printing for __devm_ioremap_resource()")
in driver-core-next.

> --- a/lib/devres.c
> +++ b/lib/devres.c
> @@ -157,8 +157,10 @@ __devm_ioremap_resource(struct device *dev, const struct resource *res,
> dev_name(dev), res->name);
> else
> pretty_name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
> - if (!pretty_name)
> + if (!pretty_name) {
> + dev_err(dev, "can't generate pretty name for resource %pR\n", res);

If the above fails, it is due to a memory allocation failure, and the
memory allocation core will have already printed an error message.
So there is no need to print a second message.
Hence IMHO this commit should be reverted.

> + }
> if (!devm_request_mem_region(dev, res->start, size, pretty_name)) {
> dev_err(dev, "can't request region for resource %pR\n", res);



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds