On Mon, Jul 10, 2023 at 12:10 PM Yangtao Li <frank.li@xxxxxxxx> wrote:
> There are more than 700 calls to devm_request_threaded_irq method and
> more than 1000 calls to devm_request_irq method. Most drivers only
> request one interrupt resource, and these error messages are basically
> the same. If error messages are printed everywhere, more than 2000 lines
> of code can be saved by removing the msg in the driver.
>
> And tglx point out that:
>
> If we actually look at the call sites of
> devm_request_threaded_irq() then the vast majority of them print more or
> less lousy error messages. A quick grep/sed/awk/sort/uniq revealed
>
> 519 messages total (there are probably more)
>
> 352 unique messages
>
> 323 unique messages after lower casing
>
> Those 323 are mostly just variants of the same patterns with
> slight modifications in formatting and information provided.
>
> 186 of these messages do not deliver any useful information,
> e.g. "no irq", "
>
> The most useful one of all is: "could request wakeup irq: %d"
>
> So there is certainly an argument to be made that this particular
> function should print a well formatted and informative error message.
>
> It's not a general allocator like kmalloc(). It's specialized and in the
> vast majority of cases failing to request the interrupt causes the
> device probe to fail. So having proper and consistent information why
> the device cannot be used _is_ useful.
>
> So convert to use devm_request*_irq_probe() API, which 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.
>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Cc: "Uwe Kleine-König" <u.kleine-koenig@xxxxxxxxxxxxxx>
> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Gr{oetje,eeting}s,
Geert
--
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
