| Message ID | 3141770d-bb58-e0e9-35ac-84cc23719892@gmail.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 378b80370aa1fe50f9c48a3ac8af3e416e73b89f |
| Delegated to: | Jiri Kosina |
| Headers | show |
| Series | hidraw: Return EPOLLOUT from hidraw_poll | expand |
On Tue, 9 Jul 2019, Fabian Henneke wrote: > Always return EPOLLOUT from hidraw_poll when a device is connected. > This is safe since writes are always possible (but will always block). > > hidraw does not support non-blocking writes and instead always calls > blocking backend functions on write requests. Hence, so far, a call to > poll never returned EPOLLOUT, which confuses tools like socat. > > Signed-off-by: Fabian Henneke <fabian.henneke@gmail.com> > In-reply-to: <CA+hv5qkyis03CgYTWeWX9cr0my-d2Oe+aZo+mjmWRXgjrGqyrw@mail.gmail.com> Good catch. I believe we need the same for hiddev too, could you please look into that as well, given you're fixing things in this area already? Thanks,
On Tue, 9 Jul 2019, Fabian Henneke wrote: > Always return EPOLLOUT from hidraw_poll when a device is connected. > This is safe since writes are always possible (but will always block). > > hidraw does not support non-blocking writes and instead always calls > blocking backend functions on write requests. Hence, so far, a call to > poll never returned EPOLLOUT, which confuses tools like socat. > > Signed-off-by: Fabian Henneke <fabian.henneke@gmail.com> > In-reply-to: <CA+hv5qkyis03CgYTWeWX9cr0my-d2Oe+aZo+mjmWRXgjrGqyrw@mail.gmail.com> Applied (together with the hiddev one) to for-5.4/hidraw-hiddev-epoll branch. Thanks,
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 006bd6f4f653..24f40a3ddded 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -252,7 +252,7 @@ static __poll_t hidraw_poll(struct file *file, poll_table *wait) poll_wait(file, &list->hidraw->wait, wait); if (list->head != list->tail) - return EPOLLIN | EPOLLRDNORM; + return EPOLLIN | EPOLLRDNORM | EPOLLOUT; if (!list->hidraw->exist) return EPOLLERR | EPOLLHUP; return 0;
Always return EPOLLOUT from hidraw_poll when a device is connected. This is safe since writes are always possible (but will always block). hidraw does not support non-blocking writes and instead always calls blocking backend functions on write requests. Hence, so far, a call to poll never returned EPOLLOUT, which confuses tools like socat. Signed-off-by: Fabian Henneke <fabian.henneke@gmail.com> In-reply-to: <CA+hv5qkyis03CgYTWeWX9cr0my-d2Oe+aZo+mjmWRXgjrGqyrw@mail.gmail.com> --- drivers/hid/hidraw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)