[PATCH v2 1/6] fb: add a line_length value to struct fb_info

[Alexander Aring]

Hi Sascha,

On Tue, Nov 05, 2013 at 09:00:57AM +0100, Sascha Hauer wrote:
> On Tue, Nov 05, 2013 at 01:06:22AM +0100, Alexander Aring wrote:
> > On Tue, Nov 05, 2013 at 12:00:59AM +0100, Andre Heider wrote:
> > > Add support for framebuffers with noncontiguous horizontal lines.
> > > 
> > > Video drivers can set this value if the hardware requires it.
> > > In case a driver does not set it, the current value of
> > > xres * (bpp / 8) is used instead.
> > > 
> > > Signed-off-by: Andre Heider <a.heider at gmail.com>
> > > ---
> > >  drivers/video/fb.c | 11 +++++++++--
> > >  include/fb.h       |  1 +
> > >  2 files changed, 10 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/video/fb.c b/drivers/video/fb.c
> > > index 420e4e3..0159994 100644
> > > --- a/drivers/video/fb.c
> > > +++ b/drivers/video/fb.c
> > > @@ -72,12 +72,16 @@ static int fb_setup_mode(struct device_d *dev, struct param_d *param,
> > >  
> > >  	info->xres = info->mode->xres;
> > >  	info->yres = info->mode->yres;
> > > +	info->line_length = 0;
> > >  
> > >  	ret = info->fbops->fb_activate_var(info);
> > >  
> > > +	if (!info->line_length)
> > > +		info->line_length = info->xres * (info->bits_per_pixel >> 3);
> > > +
> > Isn't this already set from the register_framebuffer function?
> > You wanna see that somebody changed this value in info->fbops->fb_activate_var(info)?
> > 
> > Then I would do nothing here.
> 
> It is set from register_framebuffer, but the mode setup invalidates it,
> So Andre sets it to 0 first and updates it after calling into the driver
> if necessary. The code looks correct. Maybe I misunderstand you?
> 
ok. Was a hard day and night for me ;-)
Maybe I was too tired and look all day into another code and other
things ;-).

I think I need a coffee or beer now.


I mean we have the same code in register_framebuffer:

if (!info->line_length)
        info->line_length = info->xres * (info->bits_per_pixel >> 3);

I don't know the exactly context to call fb_setup_mode but then we set
it twice and we don't need to check if the value has changed from
fb_activate_var function.

It's only a nitpick, but this code is correct. Of course.

- Alex