From c26a38b313389af157880efa8557ef894906e317 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Sat, 27 Jun 2009 16:36:21 +0100 Subject: [PATCH] [pxe] Update UNDI transmit count before transmitting packet It is possible that the UNDI ISR may be triggered before netdev_tx() returns control to pxenv_undi_transmit(). This means that pxenv_undi_isr() may see a zero undi_tx_count, and so not check for TX completions. This is not a significant problem, since it will check for TX completions on the next call to pxenv_undi_isr() anyway; it just means that the NBP will see a spurious IRQ that was apparently caused by nothing. Fix by updating the undi_tx_count before calling netdev_tx(), so that pxenv_undi_isr() can decrement it and report the TX completion. --- src/arch/i386/interface/pxe/pxe_undi.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/src/arch/i386/interface/pxe/pxe_undi.c b/src/arch/i386/interface/pxe/pxe_undi.c index e284c905..bd387ea5 100644 --- a/src/arch/i386/interface/pxe/pxe_undi.c +++ b/src/arch/i386/interface/pxe/pxe_undi.c @@ -316,18 +316,22 @@ PXENV_EXIT_t pxenv_undi_transmit ( struct s_PXENV_UNDI_TRANSMIT } } + /* Flag transmission as in-progress. Do this before starting + * to transmit the packet, because the ISR may trigger before + * we return from netdev_tx(). + */ + undi_tx_count++; + /* Transmit packet */ - DBG2 ( "\n" ); /* ISR may trigger before we return from netdev_tx() */ + DBG2 ( "\n" ); if ( ( rc = netdev_tx ( pxe_netdev, iobuf ) ) != 0 ) { DBG2 ( "PXENV_UNDI_TRANSMIT could not transmit: %s\n", strerror ( rc ) ); + undi_tx_count--; undi_transmit->Status = PXENV_STATUS ( rc ); return PXENV_EXIT_FAILURE; } - /* Flag transmission as in-progress */ - undi_tx_count++; - undi_transmit->Status = PXENV_STATUS_SUCCESS; return PXENV_EXIT_SUCCESS; }