drm/nouveau: Workaround broken TV load detection on a "Zotac FX5200".

The blob seems to have the same problem so it's probably a hardware
issue (bug 28810).

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

diff --git a/drivers/gpu/drm/nouveau/nv17_tv.c b/drivers/gpu/drm/nouveau/nv17_tv.c
index 864867e..359506e 100644 (file)
--- a/drivers/gpu/drm/nouveau/nv17_tv.c
+++ b/drivers/gpu/drm/nouveau/nv17_tv.c
@@ -116,6 +116,20 @@ static uint32_t nv42_tv_sample_load(struct drm_encoder *encoder)
        return sample;
 }
 
+static bool
+get_tv_detect_quirks(struct drm_device *dev, uint32_t *pin_mask)
+{
+       /* Zotac FX5200 */
+       if ((dev->pdev->device == 0x0322) &&
+           (dev->pdev->subsystem_vendor == 0x19da) &&
+           (dev->pdev->subsystem_device == 0x2035)) {
+               *pin_mask = 0xc;
+               return false;
+       }
+
+       return true;
+}
+
 static enum drm_connector_status
 nv17_tv_detect(struct drm_encoder *encoder, struct drm_connector *connector)
 {
@@ -124,15 +138,20 @@ nv17_tv_detect(struct drm_encoder *encoder, struct drm_connector *connector)
        struct drm_mode_config *conf = &dev->mode_config;
        struct nv17_tv_encoder *tv_enc = to_tv_enc(encoder);
        struct dcb_entry *dcb = tv_enc->base.dcb;
+       bool reliable = get_tv_detect_quirks(dev, &tv_enc->pin_mask);
 
        if (nv04_dac_in_use(encoder))
                return connector_status_disconnected;
 
-       if (dev_priv->chipset == 0x42 ||
-           dev_priv->chipset == 0x43)
-               tv_enc->pin_mask = nv42_tv_sample_load(encoder) >> 28 & 0xe;
-       else
-               tv_enc->pin_mask = nv17_dac_sample_load(encoder) >> 28 & 0xe;
+       if (reliable) {
+               if (dev_priv->chipset == 0x42 ||
+                   dev_priv->chipset == 0x43)
+                       tv_enc->pin_mask =
+                               nv42_tv_sample_load(encoder) >> 28 & 0xe;
+               else
+                       tv_enc->pin_mask =
+                               nv17_dac_sample_load(encoder) >> 28 & 0xe;
+       }
 
        switch (tv_enc->pin_mask) {
        case 0x2:
@@ -157,7 +176,9 @@ nv17_tv_detect(struct drm_encoder *encoder, struct drm_connector *connector)
                                         conf->tv_subconnector_property,
                                         tv_enc->subconnector);
 
-       if (tv_enc->subconnector) {
+       if (!reliable) {
+               return connector_status_unknown;
+       } else if (tv_enc->subconnector) {
                NV_INFO(dev, "Load detected on output %c\n",
                        '@' + ffs(dcb->or));
                return connector_status_connected;