On Sat, Nov 07, 2020 at 07:05:11PM -0800, Guenter Roeck wrote:

Hi,

I get the following build warning in v5.4.75.

drivers/hwtracing/coresight/coresight-etm-perf.c: In function 'etm_setup_aux': drivers/hwtracing/coresight/coresight-etm-perf.c:226:37: warning: passing argument 1 of 'coresight_get_enabled_sink' makes pointer from integer without a cast

Actually, the warning is fatal, since the call is sink = coresight_get_enabled_sink(true); However, the argument to coresight_get_enabled_sink() is now a pointer. The parameter change was introduced with commit 8fd52a21ab57 ("coresight: Make sysfs functional on topologies with per core sink").

In the upstream kernel, the call is removed with commit bb1860efc817 ("coresight: etm: perf: Sink selection using sysfs is deprecated"). That commit alone would, however, likely not solve the problem. It looks like at least two more commits would be needed.

716f5652a131 coresight: etm: perf: Fix warning caused by etm_setup_aux failure 8e264c52e1da coresight: core: Allow the coresight core driver to be built as a module 39a7661dcf65 coresight: Fix uninitialised pointer bug in etm_setup_aux()

Looking into the coresight code, I see several additional commits affecting the sysfs interface since v5.4. I have no idea what would actually be needed for stable code in v5.4.y, short of applying them all.

With all this in mind, I would suggest to revert commit 8fd52a21ab57 ("coresight: Make sysfs functional on topologies with per core sink") from v5.4.y, especially since it is not marked as bug fix or for stable.

I'll revert it, thanks!