| Message ID | 20230710095926.15614-13-frank.li@vivo.com (mailing list archive) |
|---|---|
| State | Under Review |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | Add devm_request_threaded_irq_probe() and devm_request_irq_probe() | expand |
On Mon, Jul 10, 2023 at 12:10 PM Yangtao Li <frank.li@vivo.com> 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@linutronix.de> > Cc: Krzysztof Kozlowski <krzk@kernel.org> > Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> > Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> > Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> > Signed-off-by: Yangtao Li <frank.li@vivo.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert
diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c index 9029d01e029b..ff9cd43e1881 100644 --- a/drivers/thermal/rcar_gen3_thermal.c +++ b/drivers/thermal/rcar_gen3_thermal.c @@ -467,9 +467,10 @@ static int rcar_gen3_thermal_request_irqs(struct rcar_gen3_thermal_priv *priv, if (!irqname) return -ENOMEM; - ret = devm_request_threaded_irq(dev, irq, NULL, - rcar_gen3_thermal_irq, - IRQF_ONESHOT, irqname, priv); + ret = devm_request_threaded_irq_probe(dev, irq, NULL, + rcar_gen3_thermal_irq, + IRQF_ONESHOT, irqname, + priv, NULL); if (ret) return ret; }
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@linutronix.de> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Yangtao Li <frank.li@vivo.com> --- drivers/thermal/rcar_gen3_thermal.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)