drm/nouveau/bios: log if auxch accesses fail, also return 0x00 from rd when it does

Logging at trace level, rather than as en error, as it seems conceivable
that failure could be normal under certain circumstances (new bios,
older sink that doesn't support a particular DPCD address)

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

diff --git a/drivers/gpu/drm/nouveau/core/subdev/bios/init.c b/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
index 626380f9e4c0192e877bef46b4a154b68c972b39..2c9f2c36f8ccb56c344e8e264e645bfc96ba9473 100644 (file)
--- a/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
@@ -278,7 +278,7 @@ init_wri2cr(struct nvbios_init *init, u8 index, u8 addr, u8 reg, u8 val)
        return -ENODEV;
 }
 
-static int
+static u8
 init_rdauxr(struct nvbios_init *init, u32 addr)
 {
        struct nouveau_i2c_port *port = init_i2c(init, -2);
@@ -286,20 +286,24 @@ init_rdauxr(struct nvbios_init *init, u32 addr)
 
        if (port && init_exec(init)) {
                int ret = nv_rdaux(port, addr, &data, 1);
-               if (ret)
-                       return ret;
-               return data;
+               if (ret == 0)
+                       return data;
+               trace("auxch read failed with %d\n", ret);
        }
 
-       return -ENODEV;
+       return 0x00;
 }
 
 static int
 init_wrauxr(struct nvbios_init *init, u32 addr, u8 data)
 {
        struct nouveau_i2c_port *port = init_i2c(init, -2);
-       if (port && init_exec(init))
-               return nv_wraux(port, addr, &data, 1);
+       if (port && init_exec(init)) {
+               int ret = nv_wraux(port, addr, &data, 1);
+               if (ret)
+                       trace("auxch write failed with %d\n", ret);
+               return ret;
+       }
        return -ENODEV;
 }