drm/nouveau: Don't try to parse a GPIO table on early DCBv2.2 BIOSes.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
index 7b7b1e27ed0b..8fc2ba164ef2 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bios.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
@@ -5809,7 +5809,7 @@ parse_dcb_gpio_table(struct nvbios *bios)
                 entries   = gpio[2];
                 recordlen = gpio[3];
         } else
-        if (dcb[0] >= 0x22) {
+        if (dcb[0] >= 0x22 && dcb[-1] >= 0x13) {
                 gpio = ROMPTR(bios, dcb[-15]);
                 if (!gpio)
                         goto no_table;
@@ -5817,6 +5817,19 @@ parse_dcb_gpio_table(struct nvbios *bios)
                 headerlen = 3;
                 entries   = gpio[2];
                 recordlen = gpio[1];
+        } else
+        if (dcb[0] >= 0x22) {
+                /* No GPIO table present, parse the TVDAC GPIO data. */
+                uint8_t *tvdac_gpio = &dcb[-5];
+
+                if (tvdac_gpio[0] & 1) {
+                        e = new_gpio_entry(bios);
+                        e->tag = DCB_GPIO_TVDAC0;
+                        e->line = tvdac_gpio[1] >> 4;
+                        e->invert = tvdac_gpio[0] & 2;
+                }
+
+                goto no_table;
         } else {
                 NV_DEBUG(dev, "no/unknown gpio table on DCB 0x%02x\n", dcb[0]);
                 goto no_table;