diff options
| author | René Rebe <rene@exactco.de> | 2026-02-05 16:49:58 +0100 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-04 07:21:19 -0500 |
| commit | b6de6d481cc22e500e0e750f9529662076e5f52e (patch) | |
| tree | 65bebbdc2fe4bdcd9366e1d803f423d5170b1d2a | |
| parent | 3ed019654234edb8625c05d05e15d40f74e64f70 (diff) | |
fbdev: ffb: fix corrupted video output on Sun FFB1
[ Upstream commit b28da0d092461ac239ff034a8ac3129320177ba3 ]
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 <rene@exactco.de>
Cc: stable@kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/video/fbdev/ffb.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/video/fbdev/ffb.c b/drivers/video/fbdev/ffb.c index e3a9bb7e9dea..e8992bdd3c9a 100644 --- a/drivers/video/fbdev/ffb.c +++ b/drivers/video/fbdev/ffb.c @@ -336,6 +336,9 @@ 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 */ @@ -426,7 +429,7 @@ 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); @@ -451,6 +454,15 @@ 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); } |