Re: [PATCH v3 0/5] introduce devm_request_threaded_irq_emsg()

Yangtao Li
2023-07-03T11:47:17Z

+cc u.kleine-koenig@pengutronix.de, krzysztof.kozlowski@linaro.org

On 2023/7/3 17:04, Yangtao Li wrote:
> There are more than 700 calls to the devm_request_threaded_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 1000 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 add devm_request_threaded_irq_emsg(), 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.
>
> Yangtao Li (5):
> genirq/devres: Add devm_request_threaded_irq_emsg()
> thermal/drivers/armada: convert to use
> devm_request_threaded_irq_emsg()
> thermal/drivers/brcmstb_thermal: convert to use
> devm_request_threaded_irq_emsg()
> thermal/drivers/db8500: convert to use
> devm_request_threaded_irq_emsg()
> thermal/drivers/mediatek/lvts_thermal: convert to use
> devm_request_threaded_irq_emsg()
>
> drivers/thermal/armada_thermal.c | 13 +++----
> drivers/thermal/broadcom/brcmstb_thermal.c | 12 +++----
> drivers/thermal/db8500_thermal.c | 16 ++++-----
> drivers/thermal/mediatek/lvts_thermal.c | 6 ++--
> include/linux/interrupt.h | 6 ++++
> kernel/irq/devres.c | 42 ++++++++++++++++++++++
> 6 files changed, 67 insertions(+), 28 deletions(-)
>