vcs: fasync(): make it consistent with poll() (fad08b20) · Commits · 戴 / test

We use POLLPRI not POLLIN to wait for data with poll() as there is never any incoming data stream per se. Let's use the same semantic with fasync() for consistency, including the fact that a vt may go away. No known user space ever relied on the SIGIO reason so far, let alone FASYNC, so the risk of breakage is pretty much nonexistent. Signed-off-by:

Nicolas Pitre <nico@linaro.org> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/vt/vc_screen.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -93,9 +93,18 @@ vcs_notifier(struct notifier_block nb, unsigned long code, void _param)
		struct vcs_poll_data *poll =
		container_of(nb, struct vcs_poll_data, notifier);
		int currcons = poll->cons_num;
		int fa_band;

		if (code != VT_UPDATE && code != VT_DEALLOCATE)
		switch (code) {
		case VT_UPDATE:
		fa_band = POLL_PRI;
		break;
		case VT_DEALLOCATE:
		fa_band = POLL_HUP;
		break;
		default:
		return NOTIFY_DONE;
		}

		if (currcons == 0)
		currcons = fg_console;
		@@ -106,7 +115,7 @@ vcs_notifier(struct notifier_block nb, unsigned long code, void _param)

		poll->event = code;
		wake_up_interruptible(&poll->waitq);
		kill_fasync(&poll->fasync, SIGIO, POLL_IN);
		kill_fasync(&poll->fasync, SIGIO, fa_band);
		return NOTIFY_OK;
		}

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