drm/i915/cmdparser: Check for SKIP descriptors first

[deliverable/linux.git] / drivers / gpu / drm / drm_dp_helper.c

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 091053e995e5b28d587efc14fca2fa21a7c746c4..5d20255f3db39fb76a6997477fb325781ebd6a78 100644 (file)
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -203,7 +203,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
 
                ret = aux->transfer(aux, &msg);
 
-               if (ret > 0) {
+               if (ret >= 0) {
                        native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
                        if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {
                                if (ret == size)
@@ -223,7 +223,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
                        err = ret;
        }
 
-       DRM_DEBUG_KMS("too many retries, giving up\n");
+       DRM_DEBUG_KMS("Too many retries, giving up. First error: %d\n", err);
        ret = err;
 
 unlock:
@@ -574,7 +574,17 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
                        if (ret == -EBUSY)
                                continue;
 
-                       DRM_DEBUG_KMS("transaction failed: %d\n", ret);
+                       /*
+                        * While timeouts can be errors, they're usually normal
+                        * behavior (for instance, when a driver tries to
+                        * communicate with a non-existant DisplayPort device).
+                        * Avoid spamming the kernel log with timeout errors.
+                        */
+                       if (ret == -ETIMEDOUT)
+                               DRM_DEBUG_KMS_RATELIMITED("transaction timed out\n");
+                       else
+                               DRM_DEBUG_KMS("transaction failed: %d\n", ret);
+
                        return ret;
                }
 
@@ -860,3 +870,35 @@ void drm_dp_aux_unregister(struct drm_dp_aux *aux)
        i2c_del_adapter(&aux->ddc);
 }
 EXPORT_SYMBOL(drm_dp_aux_unregister);
+
+#define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x)
+
+/**
+ * drm_dp_psr_setup_time() - PSR setup in time usec
+ * @psr_cap: PSR capabilities from DPCD
+ *
+ * Returns:
+ * PSR setup time for the panel in microseconds,  negative
+ * error code on failure.
+ */
+int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE])
+{
+       static const u16 psr_setup_time_us[] = {
+               PSR_SETUP_TIME(330),
+               PSR_SETUP_TIME(275),
+               PSR_SETUP_TIME(165),
+               PSR_SETUP_TIME(110),
+               PSR_SETUP_TIME(55),
+               PSR_SETUP_TIME(0),
+       };
+       int i;
+
+       i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT;
+       if (i >= ARRAY_SIZE(psr_setup_time_us))
+               return -EINVAL;
+
+       return psr_setup_time_us[i];
+}
+EXPORT_SYMBOL(drm_dp_psr_setup_time);
+
+#undef PSR_SETUP_TIME