patch "staging: speakup_soft: Fix alternate speech with other synths" added to staging-linus

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    staging: speakup_soft: Fix alternate speech with other synths

to my staging git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From 45ac7b31bc6c4af885cc5b5d6c534c15bcbe7643 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Thu, 7 Mar 2019 23:06:57 +0100
Subject: staging: speakup_soft: Fix alternate speech with other synths

When switching from speakup_soft to another synth, speakup_soft would
keep calling synth_buffer_getc() from softsynthx_read.

Let's thus make synth.c export the knowledge of the current synth, so
that speakup_soft can determine whether it should be running.

speakup_soft also needs to set itself alive, otherwise the switch would
let it remain silent.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/speakup/speakup_soft.c | 16 +++++++++++-----
 drivers/staging/speakup/spk_priv.h     |  1 +
 drivers/staging/speakup/synth.c        |  6 ++++++
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/speakup/speakup_soft.c b/drivers/staging/speakup/speakup_soft.c
index edff6ce85655..9d85a3a1af4c 100644
--- a/drivers/staging/speakup/speakup_soft.c
+++ b/drivers/staging/speakup/speakup_soft.c
@@ -210,12 +210,15 @@ static ssize_t softsynthx_read(struct file *fp, char __user *buf, size_t count,
 		return -EINVAL;
 
 	spin_lock_irqsave(&speakup_info.spinlock, flags);
+	synth_soft.alive = 1;
 	while (1) {
 		prepare_to_wait(&speakup_event, &wait, TASK_INTERRUPTIBLE);
-		if (!unicode)
-			synth_buffer_skip_nonlatin1();
-		if (!synth_buffer_empty() || speakup_info.flushing)
-			break;
+		if (synth_current() == &synth_soft) {
+			if (!unicode)
+				synth_buffer_skip_nonlatin1();
+			if (!synth_buffer_empty() || speakup_info.flushing)
+				break;
+		}
 		spin_unlock_irqrestore(&speakup_info.spinlock, flags);
 		if (fp->f_flags & O_NONBLOCK) {
 			finish_wait(&speakup_event, &wait);
@@ -235,6 +238,8 @@ static ssize_t softsynthx_read(struct file *fp, char __user *buf, size_t count,
 
 	/* Keep 3 bytes available for a 16bit UTF-8-encoded character */
 	while (chars_sent <= count - bytes_per_ch) {
+		if (synth_current() != &synth_soft)
+			break;
 		if (speakup_info.flushing) {
 			speakup_info.flushing = 0;
 			ch = '\x18';
@@ -331,7 +336,8 @@ static __poll_t softsynth_poll(struct file *fp, struct poll_table_struct *wait)
 	poll_wait(fp, &speakup_event, wait);
 
 	spin_lock_irqsave(&speakup_info.spinlock, flags);
-	if (!synth_buffer_empty() || speakup_info.flushing)
+	if (synth_current() == &synth_soft &&
+	    (!synth_buffer_empty() || speakup_info.flushing))
 		ret = EPOLLIN | EPOLLRDNORM;
 	spin_unlock_irqrestore(&speakup_info.spinlock, flags);
 	return ret;
diff --git a/drivers/staging/speakup/spk_priv.h b/drivers/staging/speakup/spk_priv.h
index c8e688878fc7..ac6a74883af4 100644
--- a/drivers/staging/speakup/spk_priv.h
+++ b/drivers/staging/speakup/spk_priv.h
@@ -74,6 +74,7 @@ int synth_request_region(unsigned long start, unsigned long n);
 int synth_release_region(unsigned long start, unsigned long n);
 int synth_add(struct spk_synth *in_synth);
 void synth_remove(struct spk_synth *in_synth);
+struct spk_synth *synth_current(void);
 
 extern struct speakup_info_t speakup_info;
 
diff --git a/drivers/staging/speakup/synth.c b/drivers/staging/speakup/synth.c
index 25f259ee4ffc..3568bfb89912 100644
--- a/drivers/staging/speakup/synth.c
+++ b/drivers/staging/speakup/synth.c
@@ -481,4 +481,10 @@ void synth_remove(struct spk_synth *in_synth)
 }
 EXPORT_SYMBOL_GPL(synth_remove);
 
+struct spk_synth *synth_current(void)
+{
+	return synth;
+}
+EXPORT_SYMBOL_GPL(synth_current);
+
 short spk_punc_masks[] = { 0, SOME, MOST, PUNC, PUNC | B_SYM };
-- 
2.21.0