Re: [PATCH 03/21] fbcon: Restore fbcon scrolling acceleration

Helge Deller
2022-02-01T10:16:36Z

On 1/31/22 22:05, Daniel Vetter wrote:
> This functionally undoes 39aead8373b3 ("fbcon: Disable accelerated
> scrolling"), but behind the FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
> option.

you have two trivial copy-n-paste errors in this patch which still prevent the
console acceleration.

> diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
> index 2ff90061c7f3..39dc18a5de86 100644
> --- a/drivers/video/fbdev/core/fbcon.c
> +++ b/drivers/video/fbdev/core/fbcon.c
> @@ -1125,13 +1125,15 @@ static void fbcon_init(struct vc_data *vc, int init)
>
> ops->graphics = 0;
>
> - /*
> - * No more hw acceleration for fbcon.
> - *
> - * FIXME: Garbage collect all the now dead code after sufficient time
> - * has passed.
> - */
> +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_ROTATION

should be:
#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION

> + if ((info->flags & FBINFO_HWACCEL_COPYAREA) &&
> + !(info->flags & FBINFO_HWACCEL_DISABLED))
> + p->scrollmode = SCROLL_MOVE;
> + else /* default to something safe */
> + p->scrollmode = SCROLL_REDRAW;
> +#else
> p->scrollmode = SCROLL_REDRAW;
> +#endif
>
> /*
> * ++guenther: console.c:vc_allocate() relies on initializing
> @@ -1971,15 +1973,49 @@ static void updatescrollmode(struct fbcon_display *p,
> {
> struct fbcon_ops *ops = info->fbcon_par;
> int fh = vc->vc_font.height;
> + int cap = info->flags;
> + u16 t = 0;
> + int ypan = FBCON_SWAP(ops->rotate, info->fix.ypanstep,
> + info->fix.xpanstep);
> + int ywrap = FBCON_SWAP(ops->rotate, info->fix.ywrapstep, t);
> int yres = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
> int vyres = FBCON_SWAP(ops->rotate, info->var.yres_virtual,
> info->var.xres_virtual);
> + int good_pan = (cap & FBINFO_HWACCEL_YPAN) &&
> + divides(ypan, vc->vc_font.height) && vyres > yres;
> + int good_wrap = (cap & FBINFO_HWACCEL_YWRAP) &&
> + divides(ywrap, vc->vc_font.height) &&
> + divides(vc->vc_font.height, vyres) &&
> + divides(vc->vc_font.height, yres);
> + int reading_fast = cap & FBINFO_READS_FAST;
> + int fast_copyarea = (cap & FBINFO_HWACCEL_COPYAREA) &&
> + !(cap & FBINFO_HWACCEL_DISABLED);
> + int fast_imageblit = (cap & FBINFO_HWACCEL_IMAGEBLIT) &&
> + !(cap & FBINFO_HWACCEL_DISABLED);
>
> p->vrows = vyres/fh;
> if (yres > (fh * (vc->vc_rows + 1)))
> p->vrows -= (yres - (fh * vc->vc_rows)) / fh;
> if ((yres % fh) && (vyres % fh < yres % fh))
> p->vrows--;
> +
> + if (good_wrap || good_pan) {
> + if (reading_fast || fast_copyarea)
> + p->scrollmode = good_wrap ?
> + SCROLL_WRAP_MOVE : SCROLL_PAN_MOVE;
> + else
> + p->scrollmode = good_wrap ? SCROLL_REDRAW :
> + SCROLL_PAN_REDRAW;
> + } else {
> + if (reading_fast || (fast_copyarea && !fast_imageblit))
> + p->scrollmode = SCROLL_MOVE;
> + else
> + p->scrollmode = SCROLL_REDRAW;
> + }
> +
> +#ifndef CONFIG_FRAMEBUFFER_CONSOLE_ROTATION

same here... it needs to be:
#ifdef CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION

> + p->scrollmode = SCROLL_REDRAW;
> +#endif
> }
>
> #define PITCH(w) (((w) + 7) >> 3)
>

still reviewing the other patches...

Helge