Re: [PATCH] gpiolib: suppress error message on EPROBE_DEFER

From: David Lechner
Date: Sat Feb 17 2018 - 22:48:12 EST


On 02/07/2018 06:57 AM, Linus Walleij wrote:
On Sun, Jan 21, 2018 at 9:32 PM, David Lechner <david@xxxxxxxxxxxxxx> wrote:

This suppresses printing an error message during probe of gpio drivers
when the error is EPROBE_DEFER.

Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>

I'm not sure about this.

GPIO can be very basic system components. If we don't
print this, defer a few times (for some reason) and then
the kernel gives up on retrying, silently (as it happens)
there is no trace in dmesg of what happened. That makes
things hard to debug.

This happened to me with some other driver, so it is not
a made up example.

What about an explicit deferral message for now?

so you mean something like this?

if (err == -EPROBE_DEFER)
dev_info(dev, "deferring probe\n")
else
dev_err(dev, "... failed to register\n")