[PATCH 3/5] fbdev: tdfxfb: Manually boot unbooted cards

From: Daniel Palmer

Date: Thu Jul 30 2026 - 14:42:13 EST


If the card is detected as being unbooted it isn't too difficult
to use the config table in its BIOS to fire it up so do it.

Signed-off-by: Daniel Palmer <daniel@xxxxxxxx>
---
drivers/video/fbdev/tdfxfb.c | 56 ++++++++++++++++++++++++++++++++----
1 file changed, 50 insertions(+), 6 deletions(-)

diff --git a/drivers/video/fbdev/tdfxfb.c b/drivers/video/fbdev/tdfxfb.c
index 1d8bffe1e9fd..4c1d847c89c9 100644
--- a/drivers/video/fbdev/tdfxfb.c
+++ b/drivers/video/fbdev/tdfxfb.c
@@ -67,6 +67,7 @@
#include <linux/aperture.h>
#include <linux/module.h>
#include <linux/kernel.h>
+#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
@@ -414,19 +415,62 @@ static bool tdfxfb_get_bios_cfg(struct pci_dev *pdev,
* Try to work out if the card was booted or not, just checks
* if the register reported memory amount matches what the BIOS
* reports for now.
+ *
+ * If we have a BIOS config table attempt to manually boot the
+ * card if needed.
*/
static int tdfxfb_hw_init(struct fb_info *info, struct pci_dev *pdev)
{
- struct tdfx_par *par = info->par;
+ u32 mempll, gfxpll, draminit0, draminit1, miscinit1, dram_mode;
struct tdfx_bios_cfg cfg;
+ bool have_cfg = tdfxfb_get_bios_cfg(pdev, &cfg);
+ struct tdfx_par *par = info->par;

- if (tdfxfb_get_bios_cfg(pdev, &cfg) &&
- tdfx_inl(par, DRAMINIT0) == le32_to_cpu(cfg.draminit0))
+ if (have_cfg && tdfx_inl(par, DRAMINIT0) == le32_to_cpu(cfg.draminit0))
return 0;

- dev_err(&pdev->dev,
- "Card hasn't booted and is unusable\n");
- return -ENODEV;
+ if (have_cfg) {
+ dev_info(&pdev->dev,
+ "Manually booting card using config table\n");
+ mempll = le32_to_cpu(cfg.pllctrl1);
+ gfxpll = le32_to_cpu(cfg.pllctrl2);
+ draminit0 = le32_to_cpu(cfg.draminit0);
+ draminit1 = le32_to_cpu(cfg.draminit1);
+ miscinit1 = le32_to_cpu(cfg.miscinit1);
+ dram_mode = le32_to_cpu(cfg.sgrammode);
+ tdfx_outl(par, PCIINIT0, le32_to_cpu(cfg.pciinit0));
+ tdfx_outl(par, AGPINIT, le32_to_cpu(cfg.agpinit0));
+ } else {
+ dev_err(&pdev->dev,
+ "Card hasn't booted and is unusable\n");
+ return -ENODEV;
+ }
+
+ /* memory clock, and the graphics clock if the card wants one */
+ tdfx_outl(par, PLLCTRL1, mempll);
+ if (gfxpll)
+ tdfx_outl(par, PLLCTRL2, gfxpll);
+ /* PLL lock */
+ udelay(100);
+
+ tdfx_outl(par, MISCINIT1, miscinit1);
+ tdfx_outl(par, DRAMINIT0, draminit0);
+ tdfx_outl(par, DRAMINIT1, draminit1);
+
+ /* Make sure the DRAM config is applied before continuing */
+ wmb();
+
+ /* SDRAM/SGRAM wake up: load the mode register */
+ tdfx_outl(par, DRAMDATA, dram_mode);
+ tdfx_outl(par, DRAMCOMMAND, 0x10d);
+
+ tdfx_outl(par, LFBMEMORYCONFIG, 0x00001fff);
+ tdfx_outl(par, MISCINIT0, 0);
+
+ /* Make sure the remaining config is applied */
+ wmb();
+
+ return 0;
}

static void do_write_regs(struct fb_info *info, struct banshee_reg *reg)
--
2.53.0