Hi,
On 10/14/2016 06:38 AM, Peter Hutterer wrote:
On Wed, Oct 12, 2016 at 04:55:08PM +0200, Hans de Goede wrote:
If the following call sequence happens:
1) InputThreadUnregisterDev(fd)
2) close(fd)
3) fd = open(...) /* returns same fd as just closed */
4) InputThreadRegisterDev(fd, ...)
Without InputThreadDoWork(); running in the mean time, then we would
keep the closed fd in the inputThreadInfo->fds pollfd set, rather then
removing it and adding the new one, causing some devices to not work
after a vt-switch when using xf86-input-evdev.
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=97880
Reported-and-tested-by: Mihail Konev <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
---
os/inputthread.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/os/inputthread.c b/os/inputthread.c
index ab1559f..c20c21c 100644
--- a/os/inputthread.c
+++ b/os/inputthread.c
@@ -49,6 +49,7 @@ Bool InputThreadEnable = TRUE;
typedef enum _InputDeviceState {
device_state_added,
+ device_state_re_added,
device_state_running,
device_state_removed
} InputDeviceState;
@@ -206,8 +207,8 @@ InputThreadRegisterDev(int fd,
if (dev) {
dev->readInputProc = readInputProc;
dev->readInputArgs = readInputArgs;
- /* Override possible unhandled state == device_state_removed */
- dev->state = device_state_running;
+ if (dev->state == device_state_removed)
+ dev->state = device_state_re_added;
I'm wondering, especially with the other patch in mind:
https://patchwork.freedesktop.org/patch/113763/
how about we just treat InputThreadDevice in state device_state_removed as
"invisible" to InputThreadRegisterDev, i.e. we don't re-use the struct but
allocate a new one. This way we have the old fd automatically removed and
the new one added as expected, skipping the need for the
device_state_re_added handling.
This would be only a one-line change a bit above this hunk
- if (old->fd == fd) {
+ if (old->fd == fd && dev->state != device_state_removed) {
The only drawback is that we rely on xorg_list_append() and that the new
entry is later than the previous one so we have the same remove/add order as
in your device_state_re_added handling below. That needs a comment
but other than that we should get the same result?
I agree that as long as we can somehow guarantee that the ospoll_remove
happens before the ospoll_add that we can then simply fix this by not
re-using the struct.
Regards,
Hans
Cheers,
Peter
} else {
dev = calloc(1, sizeof(InputThreadDevice));
if (dev == NULL) {
@@ -344,6 +345,16 @@ InputThreadDoWork(void *arg)
ospoll_listen(inputThreadInfo->fds, dev->fd,
X_NOTIFY_READ);
dev->state = device_state_running;
break;
+ case device_state_re_added:
+ /* Device might use a new fd with the same number */
+ ospoll_remove(inputThreadInfo->fds, dev->fd);
+ ospoll_add(inputThreadInfo->fds, dev->fd,
+ ospoll_trigger_level,
+ InputReady,
+ dev);
+ ospoll_listen(inputThreadInfo->fds, dev->fd,
X_NOTIFY_READ);
+ dev->state = device_state_running;
+ break;
case device_state_running:
break;
case device_state_removed:
--
2.9.3
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_______________________________________________
[email protected]: X.Org development
Archives: http://lists.x.org/archives/xorg-devel
Info: https://lists.x.org/mailman/listinfo/xorg-devel
