[PATCH] efinet: check for broken firmware

[Josef Bacik]

The firmware bug I've been tracking down has been too extensive to work around
effectively.  Basically once we switch to EXCLUSIVE everything is completely
horked.  I can add a multicast filter but it's timing sensitive, so it has to be
done at least 10 seconds after initialization for it to take place, and we have
to continue to enable PROMISCUOUS_MULTICAST because otherwise we no longer get
unicast traffic.  I discovered however that if we do not make the EXCLUSIVE
switch over everything works fine.  So instead add a function that checks for
this broken firmware and uses GET_PROTOCOL instead of EXCLUSIVE.  This also
keeps the original protocol we use when scanning the cards and leaves the
initialization stuff for ->open.  Thanks,

Signed-off-by: Josef Bacik <address@hidden>
---
 grub-core/net/drivers/efi/efinet.c | 99 ++++++++++++++++++--------------------
 1 file changed, 46 insertions(+), 53 deletions(-)

diff --git a/grub-core/net/drivers/efi/efinet.c 
b/grub-core/net/drivers/efi/efinet.c
index c8f80a1..5a207fd 100644
--- a/grub-core/net/drivers/efi/efinet.c
+++ b/grub-core/net/drivers/efi/efinet.c
@@ -156,59 +156,40 @@ get_card_packet (struct grub_net_card *dev)
 static grub_err_t
 open_card (struct grub_net_card *dev)
 {
-  grub_efi_simple_network_t *net;
+  grub_efi_simple_network_t *net = dev->efi_net;
 
-  /* Try to reopen SNP exlusively to close any active MNP protocol instance
-     that may compete for packet polling
-   */
-  net = grub_efi_open_protocol (dev->efi_handle, &net_io_guid,
-                               GRUB_EFI_OPEN_PROTOCOL_BY_EXCLUSIVE);
-  if (net)
+  if (net->mode->state == GRUB_EFI_NETWORK_STOPPED)
+    return grub_error (GRUB_ERR_NET_NO_CARD, "%s: card stopped",
+                      dev->name);
+
+  if (net->mode->state == GRUB_EFI_NETWORK_STARTED
+      && efi_call_3 (net->initialize, net, 0, 0) != GRUB_EFI_SUCCESS)
+         return grub_error (GRUB_ERR_NET_NO_CARD, "%s: net initialize failed",
+                            dev->name);
+
+  /* Enable hardware receive filters if driver declares support for it.
+     We need unicast and broadcast and additionaly all nodes and
+     solicited multicast for IPv6. Solicited multicast is per-IPv6
+     address and we currently do not have API to do it so simply
+     try to enable receive of all multicast packets or evertyhing in
+     the worst case (i386 PXE driver always enables promiscuous too).
+
+     This does trust firmware to do what it claims to do.
+    */
+  if (net->mode->receive_filter_mask)
     {
-      if (net->mode->state == GRUB_EFI_NETWORK_STOPPED
-         && efi_call_1 (net->start, net) != GRUB_EFI_SUCCESS)
-       return grub_error (GRUB_ERR_NET_NO_CARD, "%s: net start failed",
-                          dev->name);
-
-      if (net->mode->state == GRUB_EFI_NETWORK_STOPPED)
-       return grub_error (GRUB_ERR_NET_NO_CARD, "%s: card stopped",
-                          dev->name);
-
-      if (net->mode->state == GRUB_EFI_NETWORK_STARTED
-         && efi_call_3 (net->initialize, net, 0, 0) != GRUB_EFI_SUCCESS)
-       return grub_error (GRUB_ERR_NET_NO_CARD, "%s: net initialize failed",
-                          dev->name);
-
-      /* Enable hardware receive filters if driver declares support for it.
-        We need unicast and broadcast and additionaly all nodes and
-        solicited multicast for IPv6. Solicited multicast is per-IPv6
-        address and we currently do not have API to do it so simply
-        try to enable receive of all multicast packets or evertyhing in
-        the worst case (i386 PXE driver always enables promiscuous too).
-
-        This does trust firmware to do what it claims to do.
-       */
-      if (net->mode->receive_filter_mask)
-       {
-         grub_uint32_t filters = GRUB_EFI_SIMPLE_NETWORK_RECEIVE_UNICAST   |
-                                 GRUB_EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST |
-                                 
GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST;
-
-         filters &= net->mode->receive_filter_mask;
-         if (!(filters & 
GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST))
-           filters |= (net->mode->receive_filter_mask &
-                       GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS);
+      grub_uint32_t filters = GRUB_EFI_SIMPLE_NETWORK_RECEIVE_UNICAST   |
+             GRUB_EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST |
+             GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST;
 
-         efi_call_6 (net->receive_filters, net, filters, 0, 0, 0, NULL);
-       }
+      filters &= net->mode->receive_filter_mask;
+      if (!(filters & GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST))
+       filters |= (net->mode->receive_filter_mask &
+                   GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS);
 
-      efi_call_4 (grub_efi_system_table->boot_services->close_protocol,
-                 dev->efi_net, &net_io_guid,
-                 grub_efi_image_handle, dev->efi_handle);
-      dev->efi_net = net;
+      efi_call_6 (net->receive_filters, net, filters, 0, 0, 0, NULL);
     }
 
-  /* If it failed we just try to run as best as we can */
   return GRUB_ERR_NONE;
 }
 
@@ -278,12 +259,26 @@ grub_efinet_is_mac_device (struct grub_net_card *card)
   return 0;
 }
 
+static grub_efi_uint32_t
+grub_snp_attributes (void)
+{
+  /* Some firmware will completely screw up the transition to exclusive SNP,
+     doing things like not honoring receive filters or taking multiple seconds
+     to make the switch over.  So don't bother using exclusive in this case.
+   */
+  if (!grub_memcmp(grub_efi_system_table->firmware_vendor, "A", 1) &&
+      grub_efi_system_table->firmware_revision == (grub_efi_uint32_t)262798)
+    return GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL;
+  return GRUB_EFI_OPEN_PROTOCOL_BY_EXCLUSIVE;
+}
+
 static void
 grub_efinet_findcards (void)
 {
   grub_efi_uintn_t num_handles;
   grub_efi_handle_t *handles;
   grub_efi_handle_t *handle;
+  grub_efi_uint32_t attributes;
   int i = 0;
 
   /* Find handles which support the disk io interface.  */
@@ -291,6 +286,9 @@ grub_efinet_findcards (void)
                                    0, &num_handles);
   if (! handles)
     return;
+
+  attributes = grub_snp_attributes();
+
   for (handle = handles; num_handles--; handle++)
     {
       grub_efi_simple_network_t *net;
@@ -319,8 +317,7 @@ grub_efinet_findcards (void)
          && GRUB_EFI_DEVICE_PATH_SUBTYPE (parent) == 
GRUB_EFI_MAC_ADDRESS_DEVICE_PATH_SUBTYPE)
        continue;
 
-      net = grub_efi_open_protocol (*handle, &net_io_guid,
-                                   GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+      net = grub_efi_open_protocol (*handle, &net_io_guid, attributes);
       if (! net)
        /* This should not happen... Why?  */
        continue;
@@ -332,10 +329,6 @@ grub_efinet_findcards (void)
       if (net->mode->state == GRUB_EFI_NETWORK_STOPPED)
        continue;
 
-      if (net->mode->state == GRUB_EFI_NETWORK_STARTED
-         && efi_call_3 (net->initialize, net, 0, 0) != GRUB_EFI_SUCCESS)
-       continue;
-
       card = grub_zalloc (sizeof (struct grub_net_card));
       if (!card)
        {
-- 
1.8.1