On Wed, 05 Jun 2019, Ard Biesheuvel wrote: > On Wed, 5 Jun 2019 at 09:16, Lee Jones <lee.jones@xxxxxxxxxx> wrote: > > > > On Tue, 04 Jun 2019, Bjorn Andersson wrote: > > > > > On Tue 04 Jun 03:44 PDT 2019, Lee Jones wrote: > > > > > > > The Qualcomm Geni I2C driver currently probes silently which can be > > > > confusing when debugging potential issues. Add a low level (INFO) > > > > print when each I2C controller is successfully initially set-up. > > > > > > > > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> > > > > --- > > > > drivers/i2c/busses/i2c-qcom-geni.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c > > > > index 0fa93b448e8d..e27466d77767 100644 > > > > --- a/drivers/i2c/busses/i2c-qcom-geni.c > > > > +++ b/drivers/i2c/busses/i2c-qcom-geni.c > > > > @@ -598,6 +598,8 @@ static int geni_i2c_probe(struct platform_device *pdev) > > > > return ret; > > > > } > > > > > > > > + dev_info(&pdev->dev, "Geni-I2C adaptor successfully added\n"); > > > > + > > > > > > I would prefer that we do not add such prints, as it would be to accept > > > the downstream behaviour of spamming the log to the point where no one > > > will ever look through it. > > > > We should be able to find a middle ground. Spamming the log with all > > sorts of device specific information/debug is obviously not > > constructive, but a single liner to advertise that an important > > device/controller has been successfully initialised is more helpful > > than it is hinderous. > > > > This print was added due to the silent initialisation costing me > > several hours of debugging ACPI device/driver code (albeit learning a > > lot about ACPI as I go) just to find out that it was already doing the > > right thing - just very quietly. > > > > I agree. > > There are numerous EHCI drivers IIRC which, if compiled in, > unconditionally print some blurb, whether you have the hardware or > not, which is pretty annoying. > > In this case, however, having a single line per successfully probed > device (containing the dev_name and perhaps the MMIO base address or > some other identifying feature) is pretty useful, and shouldn't be > regarded as log spamming imo. dev_info() honours the 'quiet' kernel > command line parameter, and so you will only see the message if you > actually look at the log. +999 This is exactly as I see it. If people want a quiet log/fast boot-up times, they can request it. Otherwise, it's far more useful to trade a second or two for important information such as which devices are present/enabled on a platform. -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
