Re: [Qemu-devel] [PATCH v2] console: Correct computation of bytes per pixel from bits per pixel

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-08-22 17:19, BALATON Zoltan wrote:
> Division with round up is the correct way to compute this even if the
> only case where division with round down gives incorrect result is
> probably 15 bpp. This case was explicitely patched up in one of these
> functions but was unhandled in the other. (I'm not sure about setting
> 16 bpp for the 15bpp case either but I left that there for now.)
> 
> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> ---
>  console.c |    5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
>  v2: Use DIV_ROUND_UP and extended commit message
> 
> diff --git a/console.c b/console.c
> index 4525cc7..9df1701 100644
> --- a/console.c
> +++ b/console.c
> @@ -1612,7 +1612,7 @@ PixelFormat
> qemu_different_endianness_pixelformat(int bpp)
>      memset(&pf, 0x00, sizeof(PixelFormat));
> 
>      pf.bits_per_pixel = bpp;
> -    pf.bytes_per_pixel = bpp / 8;
> +    pf.bytes_per_pixel = DIV_ROUND_UP(bpp, 8);
>      pf.depth = bpp == 32 ? 24 : bpp;
> 
>      switch (bpp) {
> @@ -1661,13 +1661,12 @@ PixelFormat qemu_default_pixelformat(int bpp)
>      memset(&pf, 0x00, sizeof(PixelFormat));
> 
>      pf.bits_per_pixel = bpp;
> -    pf.bytes_per_pixel = bpp / 8;
> +    pf.bytes_per_pixel = DIV_ROUND_UP(bpp, 8);
>      pf.depth = bpp == 32 ? 24 : bpp;
> 
>      switch (bpp) {
>          case 15:
>              pf.bits_per_pixel = 16;
> -            pf.bytes_per_pixel = 2;

Removed unintentionally?

Jan

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