From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59526) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zbfdu-0007iS-NI for qemu-devel@nongnu.org; Mon, 14 Sep 2015 22:06:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zbfdq-0001jt-KG for qemu-devel@nongnu.org; Mon, 14 Sep 2015 22:06:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51638) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zbfdq-0001jo-F9 for qemu-devel@nongnu.org; Mon, 14 Sep 2015 22:06:42 -0400 Date: Tue, 15 Sep 2015 10:06:39 +0800 From: Fam Zheng Message-ID: <20150915020639.GC14016@ad.nay.redhat.com> References: <97bfdfc5cbce0bd5e0cbbbff35ce7a1bf6f8603d.1441873621.git.crosthwaite.peter@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <97bfdfc5cbce0bd5e0cbbbff35ce7a1bf6f8603d.1441873621.git.crosthwaite.peter@gmail.com> Subject: Re: [Qemu-devel] [RFT PATCH v1 2/3] net: smc91c111: gate can_receive() on rx FIFO having a slot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Crosthwaite Cc: peter.maydell@linaro.org, richard.purdie@linuxfoundation.org, qemu-devel@nongnu.org On Thu, 09/10 21:23, Peter Crosthwaite wrote: > Return false from can_receive() when the FIFO doesn't have a free RX > slot. This fixes a bug in the current code where the allocated buffer > is freed before the fifo pop, triggering a premature flush of queued RX > packets. It also will handle a corner case, where the guest manually > frees the allocated buffer before popping the rx FIFO (hence it is not > enough to just delay the flush_queued_packets()). > > Reported-by: Richard Purdie > Signed-off-by: Peter Crosthwaite > --- > > hw/net/smc91c111.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/hw/net/smc91c111.c b/hw/net/smc91c111.c > index 5774eff..8fc3deb 100644 > --- a/hw/net/smc91c111.c > +++ b/hw/net/smc91c111.c > @@ -129,7 +129,8 @@ static int smc91c111_can_receive(smc91c111_state *s) > if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST)) { > return 1; > } > - if (s->allocated == (1 << NUM_PACKETS) - 1) { > + if (s->allocated == (1 << NUM_PACKETS) - 1 || > + s->rx_fifo_len == NUM_PACKETS) { > return 0; > } > return 1; > @@ -182,6 +183,7 @@ static void smc91c111_pop_rx_fifo(smc91c111_state *s) > } else { > s->int_level &= ~INT_RCV; > } > + smc91c111_flush_queued_packets(s); > smc91c111_update(s); > } > > -- > 1.9.1 > > Reviewed-by: Fam Zheng