drm/nouveau/bios/pll: check BIT table version before trying to parse it

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pll.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pll.c
index 4cd3d6502e20..91a7dc56e406 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pll.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pll.c
@@ -81,9 +81,11 @@ static u16
 pll_limits_table(struct nvkm_bios *bios, u8 *ver, u8 *hdr, u8 *cnt, u8 *len)
 {
         struct bit_entry bit_C;
+        u16 data = 0x0000;
 
-        if (!bit_entry(bios, 'C', &bit_C) && bit_C.length >= 10) {
-                u16 data = nvbios_rd16(bios, bit_C.offset + 8);
+        if (!bit_entry(bios, 'C', &bit_C)) {
+                if (bit_C.version == 1 && bit_C.length >= 10)
+                        data = nvbios_rd16(bios, bit_C.offset + 8);
                 if (data) {
                         *ver = nvbios_rd08(bios, data + 0);
                         *hdr = nvbios_rd08(bios, data + 1);
@@ -94,7 +96,7 @@ pll_limits_table(struct nvkm_bios *bios, u8 *ver, u8 *hdr, u8 *cnt, u8 *len)
         }
 
         if (bmp_version(bios) >= 0x0524) {
-                u16 data = nvbios_rd16(bios, bios->bmp_offset + 142);
+                data = nvbios_rd16(bios, bios->bmp_offset + 142);
                 if (data) {
                         *ver = nvbios_rd08(bios, data + 0);
                         *hdr = 1;
@@ -105,7 +107,7 @@ pll_limits_table(struct nvkm_bios *bios, u8 *ver, u8 *hdr, u8 *cnt, u8 *len)
         }
 
         *ver = 0x00;
-        return 0x0000;
+        return data;
 }
 
 static struct pll_mapping *