The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From b28da0d092461ac239ff034a8ac3129320177ba3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20Rebe?= <[email protected]> Date: Thu, 5 Feb 2026 16:49:58 +0100 Subject: [PATCH] fbdev: ffb: fix corrupted video output on Sun FFB1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix Sun FFB1 corrupted video out ([1] and [2]) by disabling overlay and initializing window mode to a known state. The issue never appeared on my FFB2+/vertical nor Elite3D/M6. It could also depend on the PROM version. /SUNW,ffb@1e,0: FFB at 000001fc00000000, type 11, DAC pnum[236c] rev[10] manuf_rev[4] X (II) /dev/fb0: Detected FFB1, Z-buffer, Single-buffered. X (II) /dev/fb0: BT9068 (PAC1) ramdac detected (with normal cursor control) X (II) /dev/fb0: Detected Creator/Creator3D [1] https://www.instagram.com/p/DUTcSmSjSem/ [2] https://chaos.social/@ReneRebe/116023241660154102 Signed-off-by: René Rebe <[email protected]> Cc: [email protected] Signed-off-by: Helge Deller <[email protected]> --- drivers/video/fbdev/ffb.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/ffb.c b/drivers/video/fbdev/ffb.c index 34b6abff9493e..da531b4cb4513 100644 --- a/drivers/video/fbdev/ffb.c +++ b/drivers/video/fbdev/ffb.c @@ -335,6 +335,9 @@ struct ffb_dac { }; #define FFB_DAC_UCTRL 0x1001 /* User Control */ +#define FFB_DAC_UCTRL_OVENAB 0x00000008 /* Overlay Enable */ +#define FFB_DAC_UCTRL_WMODE 0x00000030 /* Window Mode */ +#define FFB_DAC_UCTRL_WM_COMB 0x00000000 /* Window Mode = Combined */ #define FFB_DAC_UCTRL_MANREV 0x00000f00 /* 4-bit Manufacturing Revision */ #define FFB_DAC_UCTRL_MANREV_SHIFT 8 #define FFB_DAC_TGEN 0x6000 /* Timing Generator */ @@ -425,7 +428,7 @@ static void ffb_switch_from_graph(struct ffb_par *par) { struct ffb_fbc __iomem *fbc = par->fbc; struct ffb_dac __iomem *dac = par->dac; - unsigned long flags; + unsigned long flags, uctrl; spin_lock_irqsave(&par->lock, flags); FFBWait(par); @@ -450,6 +453,15 @@ static void ffb_switch_from_graph(struct ffb_par *par) upa_writel((FFB_DAC_CUR_CTRL_P0 | FFB_DAC_CUR_CTRL_P1), &dac->value2); + /* Disable overlay and window modes. */ + upa_writel(FFB_DAC_UCTRL, &dac->type); + uctrl = upa_readl(&dac->value); + uctrl &= ~FFB_DAC_UCTRL_WMODE; + uctrl |= FFB_DAC_UCTRL_WM_COMB; + uctrl &= ~FFB_DAC_UCTRL_OVENAB; + upa_writel(FFB_DAC_UCTRL, &dac->type); + upa_writel(uctrl, &dac->value); + spin_unlock_irqrestore(&par->lock, flags); } -- 2.51.0
