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From: Jiri Slaby <jirislaby-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Daniel Vetter <daniel.vetter-/w4YWyX8dFk@public.gmane.org>,
	DRI Development
	<dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org>
Cc: Bartlomiej Zolnierkiewicz
	<b.zolnierkie-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>,
	Tetsuo Handa
	<penguin-kernel-JPay3/Yim36HaxMnTkn67Xf5DAMn2ifp@public.gmane.org>,
	nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
	"Gustavo A. R. Silva"
	<gustavoars-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Peter Rosin <peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>,
	George Kennedy
	<george.kennedy-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
	Tomi Valkeinen <tomi.valkeinen-l0cyMroinI0@public.gmane.org>,
	Ben Skeggs <bskeggs-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Greg Kroah-Hartman
	<gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>,
	Daniel Vetter
	<daniel.vetter-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Nathan Chancellor
	<natechancellor-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Linus Torvalds
	<torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
	Peilin Ye <yepeilin.cs-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH] fbcon: Disable accelerated scrolling
Date: Thu, 29 Oct 2020 06:42:39 +0100	[thread overview]
Message-ID: <997267e5-40c1-2aaf-235a-ff14f2d101e6@kernel.org> (raw)
In-Reply-To: <20201028160600.3752105-1-daniel.vetter-/w4YWyX8dFk@public.gmane.org>

On 28. 10. 20, 17:06, Daniel Vetter wrote:
> So ever since syzbot discovered fbcon, we have solid proof that it's
> full of bugs. And often the solution is to just delete code and remove
> features, e.g.  50145474f6ef ("fbcon: remove soft scrollback code").
...
> --- a/drivers/video/fbdev/core/fbcon.c
> +++ b/drivers/video/fbdev/core/fbcon.c
> @@ -1147,11 +1147,13 @@ static void fbcon_init(struct vc_data *vc, int init)
>   
>   	ops->graphics = 0;
>   
> -	if ((cap & FBINFO_HWACCEL_COPYAREA) &&
> -	    !(cap & FBINFO_HWACCEL_DISABLED))
> -		p->scrollmode = SCROLL_MOVE;
> -	else /* default to something safe */
> -		p->scrollmode = SCROLL_REDRAW;
> +	/*
> +	 * No more hw acceleration for fbcon.
> +	 *
> +	 * FIXME: Garabge collect all the now dead code after sufficient time

If you go this non-invasive path, then only a nit here: "Garbage"

thanks,
-- 
js
suse labs

WARNING: multiple messages have this Message-ID (diff)
From: Jiri Slaby <jirislaby@kernel.org>
To: Daniel Vetter <daniel.vetter@ffwll.ch>,
	DRI Development <dri-devel@lists.freedesktop.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	nouveau@lists.freedesktop.org,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	Peter Rosin <peda@axentia.se>,
	George Kennedy <george.kennedy@oracle.com>,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Ben Skeggs <bskeggs@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Daniel Vetter <daniel.vetter@intel.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peilin Ye <yepeilin.cs@gmail.com>
Subject: Re: [PATCH] fbcon: Disable accelerated scrolling
Date: Thu, 29 Oct 2020 06:42:39 +0100	[thread overview]
Message-ID: <997267e5-40c1-2aaf-235a-ff14f2d101e6@kernel.org> (raw)
In-Reply-To: <20201028160600.3752105-1-daniel.vetter@ffwll.ch>

On 28. 10. 20, 17:06, Daniel Vetter wrote:
> So ever since syzbot discovered fbcon, we have solid proof that it's
> full of bugs. And often the solution is to just delete code and remove
> features, e.g.  50145474f6ef ("fbcon: remove soft scrollback code").
...
> --- a/drivers/video/fbdev/core/fbcon.c
> +++ b/drivers/video/fbdev/core/fbcon.c
> @@ -1147,11 +1147,13 @@ static void fbcon_init(struct vc_data *vc, int init)
>   
>   	ops->graphics = 0;
>   
> -	if ((cap & FBINFO_HWACCEL_COPYAREA) &&
> -	    !(cap & FBINFO_HWACCEL_DISABLED))
> -		p->scrollmode = SCROLL_MOVE;
> -	else /* default to something safe */
> -		p->scrollmode = SCROLL_REDRAW;
> +	/*
> +	 * No more hw acceleration for fbcon.
> +	 *
> +	 * FIXME: Garabge collect all the now dead code after sufficient time

If you go this non-invasive path, then only a nit here: "Garbage"

thanks,
-- 
js
suse labs
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  parent reply	other threads:[~2020-10-29  5:42 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-28 16:06 [PATCH] fbcon: Disable accelerated scrolling Daniel Vetter
2020-10-28 16:06 ` Daniel Vetter
     [not found] ` <20201028160600.3752105-1-daniel.vetter-/w4YWyX8dFk@public.gmane.org>
2020-10-28 16:45   ` Sam Ravnborg
2020-10-28 16:45     ` Sam Ravnborg
     [not found]     ` <20201028164552.GA546379-uyr5N9Q2VtJg9hUCZPvPmw@public.gmane.org>
2020-10-28 16:48       ` Daniel Vetter
2020-10-28 16:48         ` Daniel Vetter
2020-10-28 16:57   ` Greg Kroah-Hartman
2020-10-28 16:57     ` Greg Kroah-Hartman
2020-10-28 18:50   ` Sam Ravnborg
2020-10-28 18:50     ` Sam Ravnborg
     [not found]     ` <20201028185029.GA683411-uyr5N9Q2VtJg9hUCZPvPmw@public.gmane.org>
2020-10-28 19:57       ` Daniel Vetter
2020-10-28 19:57         ` Daniel Vetter
2020-10-28 19:02   ` Thomas Zimmermann
2020-10-28 19:02     ` Thomas Zimmermann
     [not found]     ` <470585bd-74de-d652-928b-b03fe3bd8614-l3A5Bk7waGM@public.gmane.org>
2020-10-28 19:55       ` Daniel Vetter
2020-10-28 19:55         ` Daniel Vetter
     [not found]         ` <CAKMK7uEgn1ZMDpk=hnm7KODVBjUnNYiTsm-O-mDeuGRBi8qYxg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2020-10-29  8:07           ` Thomas Zimmermann
2020-10-29  8:07             ` Thomas Zimmermann
2020-10-29  5:42   ` Jiri Slaby [this message]
2020-10-29  5:42     ` Jiri Slaby
  -- strict thread matches above, loose matches on Subject: below --
2020-10-29 10:14 [Intel-gfx] [PATCH 1/3] " Daniel Vetter
     [not found] ` <20201029101428.4058311-1-daniel.vetter-/w4YWyX8dFk@public.gmane.org>
2020-10-29 13:22   ` [PATCH] " Daniel Vetter
2020-10-29 13:22     ` Daniel Vetter
     [not found]     ` <20201029132229.4068359-1-daniel.vetter-/w4YWyX8dFk@public.gmane.org>
2020-10-30  8:30       ` Tomi Valkeinen
2020-10-30  8:30         ` Tomi Valkeinen
2020-10-30  8:52         ` Daniel Vetter
2020-10-30  8:52           ` Daniel Vetter
2020-10-31 10:27     ` Geert Uytterhoeven
2020-10-31 10:27       ` Geert Uytterhoeven
2020-10-31 10:27       ` Geert Uytterhoeven
2020-10-31 14:17       ` Daniel Vetter
2020-10-31 14:17         ` Daniel Vetter
2020-10-31 14:17         ` Daniel Vetter
2020-11-18  9:21         ` Geert Uytterhoeven
2020-11-18  9:21           ` Geert Uytterhoeven
2020-11-18  9:21           ` Geert Uytterhoeven

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