On Fri, Dec 3, 2021 at 1:42 PM Philippe Mathieu-Daudé <f4...@amsat.org>
wrote:
> On 12/3/21 22:27, Patrick Venture wrote:
> > The rx_active boolean change to true should always trigger a try_read
> > call that flushes the queue.
> >
> > Signed-off-by: Patrick Venture <vent...@google.com>
> > ---
> > hw/net/npcm7xx_emc.c | 10 ++--------
> > 1 file changed, 2 insertions(+), 8 deletions(-)
> >
> > diff --git a/hw/net/npcm7xx_emc.c b/hw/net/npcm7xx_emc.c
> > index 7c892f820f..97522e6388 100644
> > --- a/hw/net/npcm7xx_emc.c
> > +++ b/hw/net/npcm7xx_emc.c
> > @@ -581,13 +581,6 @@ static ssize_t emc_receive(NetClientState *nc,
> const uint8_t *buf, size_t len1)
> > return len;
> > }
> >
> > -static void emc_try_receive_next_packet(NPCM7xxEMCState *emc)
> > -{
> > - if (emc_can_receive(qemu_get_queue(emc->nic))) {
> > - qemu_flush_queued_packets(qemu_get_queue(emc->nic));
> > - }
> > -}
>
> What about modifying as emc_flush_rx() or emc_receive_and_flush()
> helper instead?
>
> static void emc_flush_rx(NPCM7xxEMCState *emc)
> {
> emc->rx_active = true;
> qemu_flush_queued_packets(qemu_get_queue(emc->nic));
> }
>
I'm ok with that idea, although I'm less fond that it _hides_ the
rx_active=true. There is an emc_halt_rx that hides rx_active=false, so one
could argue it's not an issue. Looking at ftgmac100, it mostly just calls
the qemu_flush_queued_packets inline where it needs it. So given the prior
art, I'm more inclined to leave this as a two-line pair, versus collapsing
it into a method. Mostly because I don't anticipate this call being made
from any other places, so it's not a "growing" device. The method
originally was emc_try_receive_next_packet, which didn't do anything more
than a no-op check and the queue_flush. The new method would move the
rx_active setting from the call that deliberately controls it (the register
change) into a subordinate method...
Beyond all that, I think it's fine either way. Feel free to push back and
I'll make the change.
>
> > static uint64_t npcm7xx_emc_read(void *opaque, hwaddr offset, unsigned
> size)
> > {
> > NPCM7xxEMCState *emc = opaque;
> > @@ -704,6 +697,7 @@ static void npcm7xx_emc_write(void *opaque, hwaddr
> offset,
> > }
> > if (value & REG_MCMDR_RXON) {
> > emc->rx_active = true;
> > + qemu_flush_queued_packets(qemu_get_queue(emc->nic));
> > } else {
> > emc_halt_rx(emc, 0);
> > }
> > @@ -740,7 +734,7 @@ static void npcm7xx_emc_write(void *opaque, hwaddr
> offset,
> > case REG_RSDR:
> > if (emc->regs[REG_MCMDR] & REG_MCMDR_RXON) {
> > emc->rx_active = true;
> > - emc_try_receive_next_packet(emc);
> > + qemu_flush_queued_packets(qemu_get_queue(emc->nic));
> > }
> > break;
> > case REG_MIIDA:
> >
>
>
