increase network try interval gradually

Hi all,

This patch changes GRUB net interval gradually over time to avoid timeout problems. I'm currently doing tests in a network with heavy traffic. In this network GRUB fails with the original timeout value.

---
 grub-core/net/arp.c   | 3 ++-
 grub-core/net/icmp6.c | 3 ++-
 grub-core/net/net.c   | 5 +++--
 grub-core/net/tftp.c  | 3 ++-
 include/grub/net.h    | 1 +
 5 files changed, 10 insertions(+), 5 deletions(-)

grub-core/net/arp.c +2 -1

index 3076b18..248bd4b 100644
@@ -110,7 +110,8 @@ grub_net_arp_send_request (struct grub_net_network_level_interface *inf,
 	return GRUB_ERR_NONE;
       pending_req = proto_addr->ipv4;
       have_pending = 0;
-      grub_net_poll_cards (GRUB_NET_INTERVAL, &have_pending);
+      grub_net_poll_cards (GRUB_NET_INTERVAL + (i * GRUB_NET_INTERVAL_ADDITION),
+                           &have_pending);
       if (grub_net_link_layer_resolve_check (inf, proto_addr))
 	return GRUB_ERR_NONE;
       nb.data = nbd;

grub-core/net/icmp6.c +2 -1

index 2741e6f..bbc9020 100644
@@ -518,7 +518,8 @@ grub_net_icmp6_send_request (struct grub_net_network_level_interface *inf,
     {
       if (grub_net_link_layer_resolve_check (inf, proto_addr))
 	break;
-      grub_net_poll_cards (GRUB_NET_INTERVAL, 0);
+      grub_net_poll_cards (GRUB_NET_INTERVAL + (i * GRUB_NET_INTERVAL_ADDITION),
+                           0);
       if (grub_net_link_layer_resolve_check (inf, proto_addr))
 	break;
       nb->data = nbd;

grub-core/net/net.c +3 -2

index 8f9d183..683ab28 100644
@@ -1596,8 +1596,9 @@ grub_net_fs_read_real (grub_file_t file, char *buf, grub_size_t len)
       if (!net->eof)
 	{
 	  try++;
-	  grub_net_poll_cards (GRUB_NET_INTERVAL, &net->stall);
-	}
+	  grub_net_poll_cards (GRUB_NET_INTERVAL +
+                               (try * GRUB_NET_INTERVAL_ADDITION), &net->stall);
+        }
       else
 	return total;
     }

grub-core/net/tftp.c +2 -1

index 9c489f1..5173614 100644
@@ -398,7 +398,8 @@ tftp_open (struct grub_file *file, const char *filename)
 	  destroy_pq (data);
 	  return err;
 	}
-      grub_net_poll_cards (GRUB_NET_INTERVAL, &data->have_oack);
+      grub_net_poll_cards (GRUB_NET_INTERVAL + (i * GRUB_NET_INTERVAL_ADDITION),
+                           &data->have_oack);
       if (data->have_oack)
 	break;
     }

include/grub/net.h +1 -0

index 843f74f..538baa3 100644
@@ -536,5 +536,6 @@ extern char *grub_net_default_server;
 
 #define GRUB_NET_TRIES 40
 #define GRUB_NET_INTERVAL 400
+#define GRUB_NET_INTERVAL_ADDITION 20
 
 #endif /* ! GRUB_NET_HEADER */