Le 02/06/2015 13:05, Aurelien Jarno a écrit :
On 2015-05-27 14:19, Hervé Poussineau wrote:
Datasheet clearly says that RXDIS flag prevents reception, but says
nothing about a required presence of RXEN flag.
While at it, fix the style of the following if statement.
Signed-off-by: Hervé Poussineau <[email protected]>
---
hw/net/dp8393x.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 95a4d3d..b81036a 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -622,10 +622,12 @@ static int dp8393x_can_receive(NetClientState *nc)
{
dp8393xState *s = qemu_get_nic_opaque(nc);
- if (!(s->regs[SONIC_CR] & SONIC_CR_RXEN))
+ if (s->regs[SONIC_CR] & SONIC_CR_RXDIS) {
return 0;
- if (s->regs[SONIC_ISR] & SONIC_ISR_RBE)
+ }
+ if (s->regs[SONIC_ISR] & SONIC_ISR_RBE) {
return 0;
+ }
return 1;
}
I don't have the datasheet at hand, but what would be the point of such
a RXEN flag if it is ignored? Are you sure it's not because it's enabled
by default?
After double checking the datasheet:
- RXEN "enables the receive buffer management [...]. Setting this bit resets the
RXDIS bit"
- "Setting [RXDIS] disables the receiver from buffering data to memory or the
Receive FIFO. [...] The RXEN bit is reset when the receiver is disabled."
So RXEN and RXDIS are mutually exclusive, except in transition phases when a
packet is currently received and you're setting RXEN/RXDIS.
As QEMU doesn't emulate the period of reception of a packet (packet is received
at once), both flag checks are equivalent.
So, I'll withdraw this patch in v3.
Hervé
