From 23aa4db78aa7da994ae12d85acf7413ba2517946 Mon Sep 17 00:00:00 2001 From: Ondrej Zary Date: Mon, 24 Aug 2015 21:37:26 +0200 Subject: [PATCH] tridentfb: Fix set_lwidth on TGUI9440 and CYBER9320 According to X.Org driver, chips older than TGUI9660 have only 1 width bit in AddColReg. Touching the 2nd one causes I2C/DDC to fail on TGUI9440. Set only 1 bit of width in AddColReg on TGUI9440 and CYBER9320. Signed-off-by: Ondrej Zary Signed-off-by: Tomi Valkeinen --- drivers/video/fbdev/tridentfb.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/video/fbdev/tridentfb.c b/drivers/video/fbdev/tridentfb.c index 742971304717..01b43e9ce941 100644 --- a/drivers/video/fbdev/tridentfb.c +++ b/drivers/video/fbdev/tridentfb.c @@ -673,8 +673,14 @@ static int get_nativex(struct tridentfb_par *par) static inline void set_lwidth(struct tridentfb_par *par, int width) { write3X4(par, VGA_CRTC_OFFSET, width & 0xFF); - write3X4(par, AddColReg, - (read3X4(par, AddColReg) & 0xCF) | ((width & 0x300) >> 4)); + /* chips older than TGUI9660 have only 1 width bit in AddColReg */ + /* touching the other one breaks I2C/DDC */ + if (par->chip_id == TGUI9440 || par->chip_id == CYBER9320) + write3X4(par, AddColReg, + (read3X4(par, AddColReg) & 0xEF) | ((width & 0x100) >> 4)); + else + write3X4(par, AddColReg, + (read3X4(par, AddColReg) & 0xCF) | ((width & 0x300) >> 4)); } /* For resolutions smaller than FP resolution stretch */ -- 2.39.5