Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 1 | From: Peter Crosthwaite <crosthwaitepeter@gmail.com> |
| 2 | X-Google-Original-From: Peter Crosthwaite <crosthwaite.peter@gmail.com> |
| 3 | To: qemu-devel@nongnu.org |
| 4 | Cc: peter.maydell@linaro.org, richard.purdie@linuxfoundation.org |
| 5 | Subject: [RFT PATCH v1 2/3] net: smc91c111: gate can_receive() on rx FIFO |
| 6 | having a slot |
| 7 | Date: Thu, 10 Sep 2015 21:23:57 -0700 |
| 8 | |
| 9 | Return false from can_receive() when the FIFO doesn't have a free RX |
| 10 | slot. This fixes a bug in the current code where the allocated buffer |
| 11 | is freed before the fifo pop, triggering a premature flush of queued RX |
| 12 | packets. It also will handle a corner case, where the guest manually |
| 13 | frees the allocated buffer before popping the rx FIFO (hence it is not |
| 14 | enough to just delay the flush_queued_packets()). |
| 15 | |
| 16 | Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org> |
| 17 | Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com> |
| 18 | |
| 19 | Upstream-Status: Submitted |
| 20 | --- |
| 21 | |
| 22 | hw/net/smc91c111.c | 4 +++- |
| 23 | 1 file changed, 3 insertions(+), 1 deletion(-) |
| 24 | |
| 25 | Index: qemu-2.4.0/hw/net/smc91c111.c |
| 26 | =================================================================== |
| 27 | --- qemu-2.4.0.orig/hw/net/smc91c111.c |
| 28 | +++ qemu-2.4.0/hw/net/smc91c111.c |
| 29 | @@ -129,7 +129,8 @@ static int smc91c111_can_receive(smc91c1 |
| 30 | if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST)) { |
| 31 | return 1; |
| 32 | } |
| 33 | - if (s->allocated == (1 << NUM_PACKETS) - 1) { |
| 34 | + if (s->allocated == (1 << NUM_PACKETS) - 1 || |
| 35 | + s->rx_fifo_len == NUM_PACKETS) { |
| 36 | return 0; |
| 37 | } |
| 38 | return 1; |
| 39 | @@ -182,6 +183,7 @@ static void smc91c111_pop_rx_fifo(smc91c |
| 40 | } else { |
| 41 | s->int_level &= ~INT_RCV; |
| 42 | } |
| 43 | + smc91c111_flush_queued_packets(s); |
| 44 | smc91c111_update(s); |
| 45 | } |
| 46 | |