speakup-r empty line lockup

[Okash Khawaja]

Hi,

On Mon, Aug 21, 2017 at 12:23:46PM -0400, John Covici wrote:
> He rewrote the whole part of the code, adding some new features as
> well, so the bug mysteriously went away.

I still think the root cause is correct, i.e. interrupt being triggered
from its own interrupt handler context. The fix however was too broad.
First one changed the behaviour in all cases. Second one from last night
narrowed the change to just the interrupt context.

If I had right serial synth, I would try the attached patch. This
narrows the fix down even further, so that we avoid calling
speakup_fake_down_arrow() only when we are in context of
keyboard_notifier_call() which is always invoked in interrupt context,
in response to a keyboard event.

Thanks,
Okash
-------------- next part --------------
---
 drivers/staging/speakup/main.c |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

--- a/drivers/staging/speakup/main.c
+++ b/drivers/staging/speakup/main.c
@@ -1376,6 +1376,8 @@ static void reset_highlight_buffers(stru
 
 static int read_all_key;
 
+static volatile int in_keyboard_notifier = 0;
+
 static void start_read_all_timer(struct vc_data *vc, int command);
 
 enum {
@@ -1408,7 +1410,10 @@ static void read_all_doc(struct vc_data
 	cursor_track = read_all_mode;
 	spk_reset_index_count(0);
 	if (get_sentence_buf(vc, 0) == -1) {
-		kbd_fakekey2(vc, RA_DOWN_ARROW);
+		del_timer(&cursor_timer);
+		if (!in_keyboard_notifier)
+			speakup_fake_down_arrow();
+		start_read_all_timer(vc, RA_DOWN_ARROW);
 	} else {
 		say_sentence_num(0, 0);
 		synth_insert_next_index(0);
@@ -2212,8 +2217,10 @@ static int keyboard_notifier_call(struct
 	int ret = NOTIFY_OK;
 	static int keycode;	/* to hold the current keycode */
 
+	in_keyboard_notifier = 1;
+
 	if (vc->vc_mode == KD_GRAPHICS)
-		return ret;
+		goto out;
 
 	/*
 	 * First, determine whether we are handling a fake keypress on
@@ -2225,7 +2232,7 @@ static int keyboard_notifier_call(struct
 	 */
 
 	if (speakup_fake_key_pressed())
-		return ret;
+		goto out;
 
 	switch (code) {
 	case KBD_KEYCODE:
@@ -2266,6 +2273,8 @@ static int keyboard_notifier_call(struct
 			break;
 		}
 	}
+out:
+	in_keyboard_notifier = 0;
 	return ret;
 }