[U-Boot] [PATCH 1/2] video:cache:fix: Proper buffer alignment for lcd subsystem

[Lukasz Majewski]

Hi Simon,

> Hi Lukasz,
> 
> On Mon, Jan 7, 2013 at 1:23 AM, Lukasz Majewski
> <l.majewski at samsung.com> wrote:
> > This commit makes the video subsystem code cache aware.
> > Memory allocated for decompressed BMP memory is now cache line
> > aligned.
> >
> > Tested-by: Lukasz Majewski <l.majewski at samsung.com>
> > Signed-off-by: Lukasz Majewski <l.majewski at samsung.com>
> > Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> > Cc: Anatolij Gustschin <agust at denx.de>
> > ---
> >  common/cmd_bmp.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/common/cmd_bmp.c b/common/cmd_bmp.c
> > index 5a52edd..57f3eb5 100644
> > --- a/common/cmd_bmp.c
> > +++ b/common/cmd_bmp.c
> > @@ -55,7 +55,7 @@ bmp_image_t *gunzip_bmp(unsigned long addr,
> > unsigned long *lenp)
> >          * Decompress bmp image
> >          */
> >         len = CONFIG_SYS_VIDEO_LOGO_MAX_SIZE;
> > -       dst = malloc(CONFIG_SYS_VIDEO_LOGO_MAX_SIZE);
> > +       dst = memalign(CONFIG_SYS_CACHELINE_SIZE, len);
> >         if (dst == NULL) {
> >                 puts("Error: malloc in gunzip failed!\n");
> >                 return NULL;
> 
> Sorry, I still have a question. Does this 'dst' address get used as
> the actual LCD frame buffer on your board, or is it just copied to the
> frame buffer?
> 

I must admit, that I've misunderstood the LCD code a bit. Reply to this
post from Anatolij helped me.
The buffer (dst) is only the "internal" buffer from which we are
assigning BMP data to actual frame buffer area. Then only the frame
buffer (pointed by fb pointer) area needs cache flush (which is done at
lcd_sync()).

To sum up - this patch shall be dropped.
However the second patch - 

[PATCH 2/2] video:cache:fix:trats: Enable dcache flush for TRATS
board's LCD subsystem

is crucial to fix the BMP image display distortion.

> Regards,
> Simon
> 
> > --
> > 1.7.2.3
> >


-- 
Best regards,

Lukasz Majewski

Samsung R&D Poland (SRPOL) | Linux Platform Group