[patch] staging: speakup: check for null before calling TTY's flush_buffer

[Samuel Thibault]

Okash Khawaja, on mer. 31 mai 2017 13:55:54 +0100, wrote:
> We should check the flush_buffer method of a tty for null before
> invoking it. Some drivers such as usbserial don't implement
> flush_buffer. This will be required for upcoming patches where we expand
> spk_ttyio to support more than just ttyS*.
> 
> Signed-off-by: Okash Khawaja <okash.khawaja at gmail.com>

Reviewed-by: Samuel Thibault <samuel.thibault at ens-lyon.org>

> 
> ---
>  drivers/staging/speakup/spk_ttyio.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> --- a/drivers/staging/speakup/spk_ttyio.c
> +++ b/drivers/staging/speakup/spk_ttyio.c
> @@ -227,7 +227,8 @@ static unsigned char spk_ttyio_in_nowait
>  
>  static void spk_ttyio_flush_buffer(void)
>  {
> -	speakup_tty->ops->flush_buffer(speakup_tty);
> +	if (speakup_tty->ops->flush_buffer)
> +		speakup_tty->ops->flush_buffer(speakup_tty);
>  }
>  
>  int spk_ttyio_synth_probe(struct spk_synth *synth)
> 

-- 
Samuel
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