diff options
| author | David Herrmann <dh.herrmann@gmail.com> | 2014-07-29 19:14:15 +0400 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2014-08-25 12:28:05 +0400 |
| commit | 0e0d7520064c9f5668c030afafdbcab242176195 (patch) | |
| tree | 065b9a6d5e0cd495b315040941cc93df32a7617f /Documentation/volatile-considered-harmful.txt | |
| parent | cee5aa1f81b1e88d8de05df226bfd207041954c2 (diff) | |
| download | linux-0e0d7520064c9f5668c030afafdbcab242176195.tar.xz | |
HID: uhid: simplify report-cb shutdown
The report-query is blocking, so when user-space destroys a device we have
to wake up any blocking kernel context that is currently in the report-cb.
We used some broken correlation between @report_done and @running so far.
Replace it by a much more obvious use.
We now wake up the report-cb if either @report_done or @running is set.
wake_up() and wait_event() serve as implicit barriers (as they always do)
so no need to use smp_rmb/wmb directly.
Note that @report_done is never reset by anyone but the report-cb, thus
it cannot flip twice while we wait for it. And whenever we set @running,
we afterwards synchronously remove the HID device. Therefore, we wait for
all report-cbs to finish before we return. This way, @running can never
flip to true while we wait for it.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'Documentation/volatile-considered-harmful.txt')
0 files changed, 0 insertions, 0 deletions