a5c4c0909a
[ Upstream commit e0f0ae838a25464179d37f355d763f9ec139fc15 ]
The pm8xxx_get_channel() implementation is unclear, and causes gcc to
suddenly generate odd warnings. The trigger for the warning (at least
for me) was the entirely unrelated commit 79a4e91d1bb2 ("device.h: Add
__cold to dev_<level> logging functions"), which apparently changes gcc
code generation in the caller function enough to cause this:
drivers/iio/adc/qcom-pm8xxx-xoadc.c: In function ‘pm8xxx_xoadc_probe’:
drivers/iio/adc/qcom-pm8xxx-xoadc.c:633:8: warning: ‘ch’ may be used uninitialized in this function [-Wmaybe-uninitialized]
ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV4,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
&read_nomux_rsv4, true);
~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/adc/qcom-pm8xxx-xoadc.c:426:27: note: ‘ch’ was declared here
struct pm8xxx_chan_info *ch;
^~
because gcc for some reason then isn't able to see that the termination
condition for the "for( )" loop in that function is also the condition
for returning NULL.
So it's not _actually_ uninitialized, but the function is admittedly
just unnecessarily oddly written.
Simplify and clarify the function, making gcc also see that it always
returns a valid initialized value.
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.