Subject: linux-next: build failure after merge of the driver-core tree

From: Mark Brown <[email-masked]>
Date: Wed, 18 Sep 2019 18:09:52 +0100

Hi all,

After merging the driver-core tree, today's linux-next build
for arm64 allmodconfig failed like this:

/home/broonie/next/next/drivers/i2c/i2c-core-acpi.c: In function 'i2c_acpi_find_adapter_by_handle':
/home/broonie/next/next/drivers/i2c/i2c-core-acpi.c:352:10: error: 'i2c_acpi_find_match_adapter' undeclared (first use in this function); did you mean 'i2c_acpi_find_bus_speed'?
          i2c_acpi_find_match_adapter);
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
          i2c_acpi_find_bus_speed
/home/broonie/next/next/drivers/i2c/i2c-core-acpi.c:352:10: note: each undeclared identifier is reported only once for each function it appears in

Caused by commit

  644bf600889554210 ("i2c: Revert incorrect conversion to use generic helper")

In yesterday's -next that function existed but it appears to have been
removed in Linus' tree as part of the merge:

  4feaab05dc1eda3 ("Merge tag 'leds-for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds")

by the commit

  00500147cbd3fc5 ("drivers: Introduce device lookup variants by ACPI_COMPANION device")

(ie, the commit that the failing commit was trying to revert.)  I
suspect this is confusion caused by things going into Linus' tree in
different orders.  I've fixed this up by re-adding the function.