| Message ID | 1346248191-15316-2-git-send-email-marex@denx.de |
|---|---|
| State | Accepted |
| Delegated to: | Joe Hershberger |
| Headers | show |
Hi Marek, On Wed, Aug 29, 2012 at 8:49 AM, Marek Vasut <marex@denx.de> wrote: > The mechanism waiting for transmission to finish in fec_send() now > relies on the E-bit being cleared in the TX buffer descriptor. In > case of data cache being on, this means invalidation of data cache > above this TX buffer descriptor on each test for the E-bit being > cleared. > > Apparently, there is another way to check if the transmission did > complete. This is by checking the TDAR bit in the X_DES_ACTIVE > register. Reading a register does not need any data cache invalidation, > which is beneficial. > > Rework the sequence that wait for completion of the transmission so that > the TDAR bit is tested first and afterwards check the E-bit being clear. > This cuts down the number of cache invalidation calls to one. > > Signed-off-by: Marek Vasut <marex@denx.de> > Cc: Joe Hershberger <joe.hershberger@ni.com> > Cc: Fabio Estevam <festevam@gmail.com> > Cc: Otavio Salvador <otavio@ossystems.com.br> > Cc: Stefano Babic <sbabic@denx.de> > --- Applied, thanks. -Joe
diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c index 6f071e9..6ede464 100644 --- a/drivers/net/fec_mxc.c +++ b/drivers/net/fec_mxc.c @@ -768,19 +768,21 @@ static int fec_send(struct eth_device *dev, void *packet, int length) * invalidate data cache to see what's really in RAM. Also, we need * barrier here. */ - invalidate_dcache_range(addr, addr + size); - while (readw(&fec->tbd_base[fec->tbd_index].status) & FEC_TBD_READY) { - udelay(1); - invalidate_dcache_range(addr, addr + size); - if (!timeout--) { - ret = -EINVAL; + while (--timeout) { + if (!(readl(&fec->eth->x_des_active) & (1 << 24))) break; - } } - debug("fec_send: status 0x%x index %d\n", + if (!timeout) + ret = -EINVAL; + + invalidate_dcache_range(addr, addr + size); + if (readw(&fec->tbd_base[fec->tbd_index].status) & FEC_TBD_READY) + ret = -EINVAL; + + debug("fec_send: status 0x%x index %d ret %i\n", readw(&fec->tbd_base[fec->tbd_index].status), - fec->tbd_index); + fec->tbd_index, ret); /* for next transmission use the other buffer */ if (fec->tbd_index) fec->tbd_index = 0;
The mechanism waiting for transmission to finish in fec_send() now relies on the E-bit being cleared in the TX buffer descriptor. In case of data cache being on, this means invalidation of data cache above this TX buffer descriptor on each test for the E-bit being cleared. Apparently, there is another way to check if the transmission did complete. This is by checking the TDAR bit in the X_DES_ACTIVE register. Reading a register does not need any data cache invalidation, which is beneficial. Rework the sequence that wait for completion of the transmission so that the TDAR bit is tested first and afterwards check the E-bit being clear. This cuts down the number of cache invalidation calls to one. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Joe Hershberger <joe.hershberger@ni.com> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de> --- drivers/net/fec_mxc.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)