5.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx> commit 45ac7b31bc6c4af885cc5b5d6c534c15bcbe7643 upstream. 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@xxxxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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(-) --- a/drivers/staging/speakup/speakup_soft.c +++ b/drivers/staging/speakup/speakup_soft.c @@ -208,12 +208,15 @@ static ssize_t softsynthx_read(struct fi 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); @@ -233,6 +236,8 @@ static ssize_t softsynthx_read(struct fi /* 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'; @@ -329,7 +334,8 @@ static __poll_t softsynth_poll(struct fi 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; --- a/drivers/staging/speakup/spk_priv.h +++ b/drivers/staging/speakup/spk_priv.h @@ -74,6 +74,7 @@ int synth_request_region(unsigned long s 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; --- a/drivers/staging/speakup/synth.c +++ b/drivers/staging/speakup/synth.c @@ -481,4 +481,10 @@ void synth_remove(struct spk_synth *in_s } 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 };