Re: [PATCH 06/21] fbcon: delete delayed loading code

Daniel Vetter
2022-02-08T13:42:31Z

On Thu, Feb 03, 2022 at 09:45:29PM +0100, Sam Ravnborg wrote:
> Hi Daniel,
>
> On Mon, Jan 31, 2022 at 10:05:37PM +0100, Daniel Vetter wrote:
> > Before
> >
> > commit 6104c37094e729f3d4ce65797002112735d49cd1
> > Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Date: Tue Aug 1 17:32:07 2017 +0200
> >
> > fbcon: Make fbcon a built-time depency for fbdev
> >
> > it was possible to load fbcon and fbdev drivers in any order, which
> > means that fbcon init had to handle the case where fbdev drivers where
> > already registered.
> >
> > This is no longer possible, hence delete that code.
> >
> > Note that the exit case is a bit more complex and will be done in a
> > separate patch.
> >
> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > Cc: Helge Deller <deller@gmx.de>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: Claudio Suarez <cssk@net-c.es>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> > Cc: Du Cheng <ducheng2@gmail.com>
> > ---
> > drivers/video/fbdev/core/fbcon.c | 13 +------------
> > 1 file changed, 1 insertion(+), 12 deletions(-)
> >
> > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
> > index 8f971de35885..814b648e8f09 100644
> > --- a/drivers/video/fbdev/core/fbcon.c
> > +++ b/drivers/video/fbdev/core/fbcon.c
> > @@ -942,7 +942,7 @@ static const char *fbcon_startup(void)
> > return display_desc;
> > /*
> > * Instead of blindly using registered_fb[0], we use info_idx, set by
> > - * fb_console_init();
> > + * fbcon_fb_registered();
> > */
> This comment change looks like it does not belong in this patch.
> Also, the comment is wrong as info_idx is set in several places.
> Like set_con2fb_map(), fbcon_remap_all(), and more.

Yeah I can split this out into a separate patch, but I spotted this wrong
comment as part of reviewing this code change here - essentially you have
to check how fb_info for fbcon are registered and fbcon init happens to
validate that deleting the below code is correct.

Ok if I put this explainer into the commit message, or do you want me to
split this out fully?
-Daniel

>
> Though it is not set by fb_console_init - so partly OK.
>
> With the comment adjustment dropped.
> Acked-by: Sam Ravnborg <sam@ravnborg.org>
>
> at least the code deletion looked OK, I failed to follow all the logic.
> So would be good if someone else could ack it too.
>
> Sam
>
>
>
> > info = registered_fb[info_idx];
> > if (!info)
> > @@ -3316,17 +3316,6 @@ static void fbcon_start(void)
> > return;
> > }
> > #endif
> > -
> > - if (num_registered_fb) {
> > - int i;
> > -
> > - for_each_registered_fb(i) {
> > - info_idx = i;
> > - break;
> > - }
> > -
> > - do_fbcon_takeover(0);
> > - }
> > }
> >
> > static void fbcon_exit(void)
> > --
> > 2.33.0

--
Daniel Vetter
Software Engineer, Intel Corporation