[PATCH] efi_loader: Set EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT again in efi_net_receive()

[Masami Hiramatsu]

From: Kazuhiko Sakamoto <sakamoto.kazuhiko at socionext.com>

Since 'this->int_status' is cleared by efi_net_get_status(), if user
does wait_for_event(wait_for_packet) and efi_net_get_status() loop
and there are several received packets on the buffer, the second
efi_net_get_status() does not return EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT
even if the 'wait_for_packet' is ready.

This happens on "efiboot selftest" with noisy network.
(The network device can receive both of other packets and dhcp discover
 packet in a short time.)

Set EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT again when we found any
packet still on the receive buffer.

Signed-off-by: Kazuhiko Sakamoto <sakamoto.kazuhiko at socionext.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu at linaro.org>
---
 lib/efi_loader/efi_net.c |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/lib/efi_loader/efi_net.c b/lib/efi_loader/efi_net.c
index 69276b275d..9ca1e0c354 100644
--- a/lib/efi_loader/efi_net.c
+++ b/lib/efi_loader/efi_net.c
@@ -640,10 +640,19 @@ static efi_status_t EFIAPI efi_net_receive
 	*buffer_size = receive_lengths[rx_packet_idx];
 	rx_packet_idx = (rx_packet_idx + 1) % ETH_PACKETS_BATCH_RECV;
 	rx_packet_num--;
-	if (rx_packet_num)
+	if (rx_packet_num) {
+		/*
+		 * Since 'this->int_status' is cleared by efi_net_get_status(),
+		 * if user does wait_for_event(wait_for_packet) and
+		 * efi_net_get_status() again, EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT
+		 * is not set even if 'wait_for_packet' is ready.
+		 * Set EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT again here.
+		 */
+		this->int_status |= EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT;
 		wait_for_packet->is_signaled = true;
-	else
+	} else {
 		this->int_status &= ~EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT;
+	}
 out:
 	return EFI_EXIT(ret);
 }