if (ring->id == RCS)
len += 6;
+ /*
+ * BSpec MI_DISPLAY_FLIP for IVB:
+ * "The full packet must be contained within the same cache line."
+ *
+ * Currently the LRI+SRM+MI_DISPLAY_FLIP all fit within the same
+ * cacheline, if we ever start emitting more commands before
+ * the MI_DISPLAY_FLIP we may need to first emit everything else,
+ * then do the cacheline alignment, and finally emit the
+ * MI_DISPLAY_FLIP.
+ */
+ ret = intel_ring_cacheline_align(ring);
+ if (ret)
+ goto err_unpin;
+
ret = intel_ring_begin(ring, len);
if (ret)
goto err_unpin;
uint8_t msg[20];
int msg_bytes;
uint8_t ack;
+ int retry;
if (WARN_ON(send_bytes > 16))
return -E2BIG;
msg[3] = send_bytes - 1;
memcpy(&msg[4], send, send_bytes);
msg_bytes = send_bytes + 4;
- for (;;) {
+ for (retry = 0; retry < 7; retry++) {
ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes, &ack, 1);
if (ret < 0)
return ret;
ack >>= 4;
if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_ACK)
- break;
+ return send_bytes;
else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER)
- udelay(100);
+ usleep_range(400, 500);
else
return -EIO;
}
- return send_bytes;
+
+ DRM_ERROR("too many retries, giving up\n");
+ return -EIO;
}
/* Write a single byte to the aux channel in native mode */
int reply_bytes;
uint8_t ack;
int ret;
+ int retry;
if (WARN_ON(recv_bytes > 19))
return -E2BIG;
msg_bytes = 4;
reply_bytes = recv_bytes + 1;
- for (;;) {
+ for (retry = 0; retry < 7; retry++) {
ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes,
reply, reply_bytes);
if (ret == 0)
return ret - 1;
}
else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER)
- udelay(100);
+ usleep_range(400, 500);
else
return -EIO;
}
+
+ DRM_ERROR("too many retries, giving up\n");
+ return -EIO;
}
static int
return 0;
}
+/* Align the ring tail to a cacheline boundary */
+int intel_ring_cacheline_align(struct intel_ring_buffer *ring)
+{
+ int num_dwords = (64 - (ring->tail & 63)) / sizeof(uint32_t);
+ int ret;
+
+ if (num_dwords == 0)
+ return 0;
+
+ ret = intel_ring_begin(ring, num_dwords);
+ if (ret)
+ return ret;
+
+ while (num_dwords--)
+ intel_ring_emit(ring, MI_NOOP);
+
+ intel_ring_advance(ring);
+
+ return 0;
+}
+
void intel_ring_init_seqno(struct intel_ring_buffer *ring, u32 seqno)
{
struct drm_i915_private *dev_priv = ring->dev->dev_private;
void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring);
int __must_check intel_ring_begin(struct intel_ring_buffer *ring, int n);
+int __must_check intel_ring_cacheline_align(struct intel_ring_buffer *ring);
static inline void intel_ring_emit(struct intel_ring_buffer *ring,
u32 data)
{