Re: staging: speakup: flush tty buffers

[Okash Khawaja <okash.khawaja@gmail.com>]

Hi,

For testing, I have updated the github repo [1]. I will test this on apollo.

Thanks,
Okash

[1] https://github.com/bytefire/speakup-decext

On Mon, May 01, 2017 at 07:02:08PM +0100, Okash Khawaja wrote:
> This patch fixes the issue where TTY-migrated synths would take a while
> to shut up after hitting numpad enter key. When calling synth_flush, even
> though XOFF character is sent as high priority, data buffered in TTY layer
> is still sent to the synth. This patch flushes that buffered data when
> synth_flush is called.
> 
> Reported-by: John Covici <covici@ccs.covici.com>
> Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
> 
> Index: linux-staging/drivers/staging/speakup/serialio.c
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/serialio.c
> +++ linux-staging/drivers/staging/speakup/serialio.c
> @@ -30,6 +30,7 @@
>  static void spk_serial_tiocmset(unsigned int set, unsigned int clear);
>  static unsigned char spk_serial_in(void);
>  static unsigned char spk_serial_in_nowait(void);
> +static void spk_serial_flush_buffer(void);
>  
>  struct spk_io_ops spk_serial_io_ops = {
>  	.synth_out = spk_serial_out,
> @@ -37,6 +38,7 @@
>  	.tiocmset = spk_serial_tiocmset,
>  	.synth_in = spk_serial_in,
>  	.synth_in_nowait = spk_serial_in_nowait,
> +	.flush_buffer = spk_serial_flush_buffer,
>  };
>  EXPORT_SYMBOL_GPL(spk_serial_io_ops);
>  
> @@ -268,6 +270,11 @@
>  	return inb_p(speakup_info.port_tts + UART_RX);
>  }
>  
> +static void spk_serial_flush_buffer(void)
> +{
> +	/* TODO: flush the UART 16550 buffer */
> +}
> +
>  static int spk_serial_out(struct spk_synth *in_synth, const char ch)
>  {
>  	if (in_synth->alive && spk_wait_for_xmitr(in_synth)) {
> Index: linux-staging/drivers/staging/speakup/spk_ttyio.c
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/spk_ttyio.c
> +++ linux-staging/drivers/staging/speakup/spk_ttyio.c
> @@ -85,6 +85,7 @@
>  static void spk_ttyio_tiocmset(unsigned int set, unsigned int clear);
>  static unsigned char spk_ttyio_in(void);
>  static unsigned char spk_ttyio_in_nowait(void);
> +static void spk_ttyio_flush_buffer(void);
>  
>  struct spk_io_ops spk_ttyio_ops = {
>  	.synth_out = spk_ttyio_out,
> @@ -92,6 +93,7 @@
>  	.tiocmset = spk_ttyio_tiocmset,
>  	.synth_in = spk_ttyio_in,
>  	.synth_in_nowait = spk_ttyio_in_nowait,
> +	.flush_buffer = spk_ttyio_flush_buffer,
>  };
>  EXPORT_SYMBOL_GPL(spk_ttyio_ops);
>  
> @@ -201,6 +203,11 @@
>  	return (rv == 0xff) ? 0 : rv;
>  }
>  
> +static void spk_ttyio_flush_buffer(void)
> +{
> +	speakup_tty->ops->flush_buffer(speakup_tty);
> +}
> +
>  int spk_ttyio_synth_probe(struct spk_synth *synth)
>  {
>  	int rv = spk_ttyio_initialise_ldisc(synth->ser);
> Index: linux-staging/drivers/staging/speakup/spk_types.h
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/spk_types.h
> +++ linux-staging/drivers/staging/speakup/spk_types.h
> @@ -154,6 +154,7 @@
>  	void (*tiocmset)(unsigned int set, unsigned int clear);
>  	unsigned char (*synth_in)(void);
>  	unsigned char (*synth_in_nowait)(void);
> +	void (*flush_buffer)(void);
>  };
>  
>  struct spk_synth {
> Index: linux-staging/drivers/staging/speakup/speakup_audptr.c
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/speakup_audptr.c
> +++ linux-staging/drivers/staging/speakup/speakup_audptr.c
> @@ -127,6 +127,7 @@
>  
>  static void synth_flush(struct spk_synth *synth)
>  {
> +	synth->io_ops->flush_buffer();
>  	synth->io_ops->send_xchar(SYNTH_CLEAR);
>  	synth->io_ops->synth_out(synth, PROCSPEECH);
>  }
> Index: linux-staging/drivers/staging/speakup/speakup_decext.c
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/speakup_decext.c
> +++ linux-staging/drivers/staging/speakup/speakup_decext.c
> @@ -221,6 +221,7 @@
>  static void synth_flush(struct spk_synth *synth)
>  {
>  	in_escape = 0;
> +	synth->io_ops->flush_buffer();
>  	synth->synth_immediate(synth, "\033P;10z\033\\");
>  }
>  
> Index: linux-staging/drivers/staging/speakup/speakup_dectlk.c
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/speakup_dectlk.c
> +++ linux-staging/drivers/staging/speakup/speakup_dectlk.c
> @@ -293,6 +293,7 @@
>  		synth->io_ops->synth_out(synth, ']');
>  	in_escape = 0;
>  	is_flushing = 1;
> +	synth->io_ops->flush_buffer();
>  	synth->io_ops->synth_out(synth, SYNTH_CLEAR);
>  }
>  
> Index: linux-staging/drivers/staging/speakup/speakup_spkout.c
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/speakup_spkout.c
> +++ linux-staging/drivers/staging/speakup/speakup_spkout.c
> @@ -125,6 +125,7 @@
>  
>  static void synth_flush(struct spk_synth *synth)
>  {
> +	synth->io_ops->flush_buffer();
>  	synth->io_ops->send_xchar(SYNTH_CLEAR);
>  }
>  
> Index: linux-staging/drivers/staging/speakup/synth.c
> ===================================================================
> --- linux-staging.orig/drivers/staging/speakup/synth.c
> +++ linux-staging/drivers/staging/speakup/synth.c
> @@ -120,6 +120,7 @@
>  
>  void spk_synth_flush(struct spk_synth *synth)
>  {
> +	synth->io_ops->flush_buffer();
>  	synth->io_ops->synth_out(synth, synth->clear);
>  }
>  EXPORT_SYMBOL_GPL(spk_synth_flush);