Re: [PATCH] Staging: speakup: read scrolled-back VT

From: covici@ccs.covici.com
To: Samuel Thibault <samuel.thibault@ens-lyon.org>,
	William Hubbs <w.d.hubbs@gmail.com>,
	Chris Brannon <chris@the-brannons.com>,
	Kirk Reiser <kirk@reisers.ca>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>,
	speakup@linux-speakup.org, devel@driverdev.osuosl.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Staging: speakup: read scrolled-back VT
Date: Fri, 01 Jan 2016 16:11:03 -0500	[thread overview]
Message-ID: <3313.1451682663@ccs.covici.com> (raw)
In-Reply-To: <20160101172039.GC2860@var.home>

Tested  on 4.1.15 and it seems to work fine -- thanks a lot.

Samuel Thibault <samuel.thibault@ens-lyon.org> wrote:

> Previously, speakup would always read the bottom part of the screen,
> even when the VT is scrolled back with shift-page.  This patch makes
> vt.c export screen_pos so that speakup can use it to properly access
> the content of the scrolled-back VT.
> 
> This was tested with both vgacon and fbcon.
> 
> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> 
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -4250,6 +4250,7 @@ unsigned short *screen_pos(struct vc_dat
>  {
>  	return screenpos(vc, 2 * w_offset, viewed);
>  }
> +EXPORT_SYMBOL_GPL(screen_pos);
>  
>  void getconsxy(struct vc_data *vc, unsigned char *p)
>  {
> --- a/drivers/staging/speakup/main.c
> +++ b/drivers/staging/speakup/main.c
> @@ -264,8 +264,9 @@ static struct notifier_block vt_notifier
>  	.notifier_call = vt_notifier_call,
>  };
>  
> -static unsigned char get_attributes(u16 *pos)
> +static unsigned char get_attributes(struct vc_data *vc, u16 *pos)
>  {
> +	pos = screen_pos(vc, pos - (u16 *)vc->vc_origin, 1);
>  	return (u_char) (scr_readw(pos) >> 8);
>  }
>  
> @@ -275,7 +276,7 @@ static void speakup_date(struct vc_data
>  	spk_y = spk_cy = vc->vc_y;
>  	spk_pos = spk_cp = vc->vc_pos;
>  	spk_old_attr = spk_attr;
> -	spk_attr = get_attributes((u_short *) spk_pos);
> +	spk_attr = get_attributes(vc, (u_short *)spk_pos);
>  }
>  
>  static void bleep(u_short val)
> @@ -469,8 +470,12 @@ static u16 get_char(struct vc_data *vc,
>  	u16 ch = ' ';
>  
>  	if (vc && pos) {
> -		u16 w = scr_readw(pos);
> -		u16 c = w & 0xff;
> +		u16 w;
> +		u16 c;
> +
> +		pos = screen_pos(vc, pos - (u16 *)vc->vc_origin, 1);
> +		w = scr_readw(pos);
> +		c = w & 0xff;
>  
>  		if (w & vc->vc_hi_font_mask)
>  			c |= 0x100;
> @@ -746,7 +751,7 @@ static int get_line(struct vc_data *vc)
>  	u_char tmp2;
>  
>  	spk_old_attr = spk_attr;
> -	spk_attr = get_attributes((u_short *) spk_pos);
> +	spk_attr = get_attributes(vc, (u_short *)spk_pos);
>  	for (i = 0; i < vc->vc_cols; i++) {
>  		buf[i] = (u_char) get_char(vc, (u_short *) tmp, &tmp2);
>  		tmp += 2;
> @@ -811,7 +816,7 @@ static int say_from_to(struct vc_data *v
>  	u_short saved_punc_mask = spk_punc_mask;
>  
>  	spk_old_attr = spk_attr;
> -	spk_attr = get_attributes((u_short *) from);
> +	spk_attr = get_attributes(vc, (u_short *)from);
>  	while (from < to) {
>  		buf[i++] = (char)get_char(vc, (u_short *) from, &tmp);
>  		from += 2;
> @@ -886,7 +891,7 @@ static int get_sentence_buf(struct vc_da
>  	sentmarks[bn][0] = &sentbuf[bn][0];
>  	i = 0;
>  	spk_old_attr = spk_attr;
> -	spk_attr = get_attributes((u_short *) start);
> +	spk_attr = get_attributes(vc, (u_short *)start);
>  
>  	while (start < end) {
>  		sentbuf[bn][i] = (char)get_char(vc, (u_short *) start, &tmp);
> @@ -1585,7 +1590,7 @@ static int count_highlight_color(struct
>  		u16 *ptr;
>  
>  		for (ptr = start; ptr < end; ptr++) {
> -			ch = get_attributes(ptr);
> +			ch = get_attributes(vc, ptr);
>  			bg = (ch & 0x70) >> 4;
>  			speakup_console[vc_num]->ht.bgcount[bg]++;
>  		}
> _______________________________________________
> Speakup mailing list
> Speakup@linux-speakup.org
> http://linux-speakup.org/cgi-bin/mailman/listinfo/speakup
> 

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici@ccs.covici.com