[PATCH 10/10] [RFC] video: fbdev: atari: Remove backward bug-compatibility

Geert Uytterhoeven
2022-07-11T15:51:05Z

As of v2.1.0, falcon_decode_var() contains a quirk to fix a rounding
error, as explained by Günther Kelleter on Fri, 30 Aug 1996:

This diff removes the now obsolete Falcon video option "pwrsave", and
fixes a rounding error that is triggered by the resolution switching X
server (those who use the pixel clock value 39722 in their /etc/fb.modes
should change it to 39721).

However, this causes the modified video mode returned by
falcon_decode_var() to not match the video mode returned by
falcon_encode_var(). Fix this by dropping the quirk.

Unfortunately /etc/fb.modes in fbset was never updated, so the
"640x480-60" mode still contains the wrong pixclock.
Hence this change may introduce a regression.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
Any comments?
---
drivers/video/fbdev/atafb.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
index e8b178e732e2c785..2bc4089865e60ac2 100644
--- a/drivers/video/fbdev/atafb.c
+++ b/drivers/video/fbdev/atafb.c
@@ -1008,10 +1008,6 @@ static int falcon_decode_var(struct fb_var_screeninfo *var,
else if (yres_virtual < yres)
yres_virtual = yres;

- /* backward bug-compatibility */
- if (var->pixclock > 1)
- var->pixclock -= 1;
-
par->hw.falcon.line_width = bpp * xres / 16;
par->hw.falcon.line_offset = bpp * (xres_virtual - xres) / 16;

--
2.25.1