1 files changed, 12 insertions, 2 deletions

diff --git a/arch/sparc/kernel/viohs.c b/arch/sparc/kernel/viohs.c
index 9c5fbd0b8a04..526fcb5d8ce9 100644
--- a/arch/sparc/kernel/viohs.c
+++ b/arch/sparc/kernel/viohs.c
@@ -426,6 +426,13 @@ static int process_dreg_info(struct vio_driver_state *vio,
         if (vio->dr_state & VIO_DR_STATE_RXREG)
                 goto send_nack;
 
+        /* v1.6 and higher, ACK with desired, supported mode, or NACK */
+        if (vio_version_after_eq(vio, 1, 6)) {
+                if (!(pkt->options & VIO_TX_DRING))
+                        goto send_nack;
+                pkt->options = VIO_TX_DRING;
+        }
+
         BUG_ON(vio->desc_buf);
 
         vio->desc_buf = kzalloc(pkt->descr_size, GFP_ATOMIC);
@@ -453,8 +460,11 @@ static int process_dreg_info(struct vio_driver_state *vio,
         pkt->tag.stype = VIO_SUBTYPE_ACK;
         pkt->dring_ident = ++dr->ident;
 
-        viodbg(HS, "SEND DRING_REG ACK ident[%llx]\n",
-               (unsigned long long) pkt->dring_ident);
+        viodbg(HS, "SEND DRING_REG ACK ident[%llx] "
+               "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
+               (unsigned long long) pkt->dring_ident,
+               pkt->num_descr, pkt->descr_size, pkt->options,
+               pkt->num_cookies);
 
         len = (sizeof(*pkt) +
                (dr->ncookies * sizeof(struct ldc_trans_cookie)));