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

[BALATON Zoltan <balaton@eik.bme.hu>]

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;
              pf.rmask = 0x00007c00;
              pf.gmask = 0x000003E0;
              pf.bmask = 0x0000001F;
-- 
1.7.10