| Message ID | 1456360619-24390-8-git-send-email-troy.kisky@boundarydevices.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
From: Troy Kisky <troy.kisky@boundarydevices.com> Sent: Thursday, February 25, 2016 8:37 AM > To: netdev@vger.kernel.org; davem@davemloft.net; b38611@freescale.com > Cc: fabio.estevam@freescale.com; l.stach@pengutronix.de; andrew@lunn.ch; > tremyfr@gmail.com; linux@arm.linux.org.uk; linux-arm- > kernel@lists.infradead.org; laci@boundarydevices.com; shawnguo@kernel.org; > johannes@sipsolutions.net; stillcompiling@gmail.com; > sergei.shtylyov@cogentembedded.com; arnd@arndb.de; Troy Kisky > <troy.kisky@boundarydevices.com> > Subject: [PATCH net-next V2 07/16] net: fec: set cbd_sc without relying on > previous value > > Relying on the wrap bit to stay valid once initialized when the controller also > writes to this byte seems undesirable since we can easily know what the value > should be. > > Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com> > --- > drivers/net/ethernet/freescale/fec_main.c | 38 +++++++++---------------------- > 1 file changed, 11 insertions(+), 27 deletions(-) > > diff --git a/drivers/net/ethernet/freescale/fec_main.c > b/drivers/net/ethernet/freescale/fec_main.c > index 791f385..6ceb5f9 100644 > --- a/drivers/net/ethernet/freescale/fec_main.c > +++ b/drivers/net/ethernet/freescale/fec_main.c > @@ -340,9 +340,8 @@ fec_enet_txq_submit_frag_skb(struct > fec_enet_priv_tx_q *txq, > bdp = fec_enet_get_nextdesc(bdp, &txq->bd); > ebdp = (struct bufdesc_ex *)bdp; > > - status = fec16_to_cpu(bdp->cbd_sc); > - status &= ~BD_ENET_TX_STATS; > - status |= (BD_ENET_TX_TC | BD_ENET_TX_READY); > + status = BD_ENET_TX_TC | BD_ENET_TX_READY | > + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); > frag_len = skb_shinfo(skb)->frags[frag].size; > > /* Handle the last BD specially */ > @@ -436,8 +435,6 @@ static int fec_enet_txq_submit_skb(struct > fec_enet_priv_tx_q *txq, > /* Fill in a Tx ring entry */ > bdp = txq->bd.cur; > last_bdp = bdp; > - status = fec16_to_cpu(bdp->cbd_sc); > - status &= ~BD_ENET_TX_STATS; > > /* Set buffer length and buffer pointer */ > bufaddr = skb->data; > @@ -462,6 +459,8 @@ static int fec_enet_txq_submit_skb(struct > fec_enet_priv_tx_q *txq, > return NETDEV_TX_OK; > } > > + status = BD_ENET_TX_TC | BD_ENET_TX_READY | > + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); > if (nr_frags) { > last_bdp = fec_enet_txq_submit_frag_skb(txq, skb, ndev); > if (IS_ERR(last_bdp)) { > @@ -512,7 +511,6 @@ static int fec_enet_txq_submit_skb(struct > fec_enet_priv_tx_q *txq, > /* Send it on its way. Tell FEC it's ready, interrupt when done, > * it's the last BD of the frame, and to put the CRC on the end. > */ > - status |= (BD_ENET_TX_READY | BD_ENET_TX_TC); This is completely error. We have to prepare all BDs for frag skb, and then enable "READY" and "TC" bit for the first BD, otherwise uDMA copy un-correct data to fifo. <snip>
On 3/4/2016 2:29 AM, Fugang Duan wrote: > From: Troy Kisky <troy.kisky@boundarydevices.com> Sent: Thursday, February 25, 2016 8:37 AM >> To: netdev@vger.kernel.org; davem@davemloft.net; b38611@freescale.com >> Cc: fabio.estevam@freescale.com; l.stach@pengutronix.de; andrew@lunn.ch; >> tremyfr@gmail.com; linux@arm.linux.org.uk; linux-arm- >> kernel@lists.infradead.org; laci@boundarydevices.com; shawnguo@kernel.org; >> johannes@sipsolutions.net; stillcompiling@gmail.com; >> sergei.shtylyov@cogentembedded.com; arnd@arndb.de; Troy Kisky >> <troy.kisky@boundarydevices.com> >> Subject: [PATCH net-next V2 07/16] net: fec: set cbd_sc without relying on >> previous value >> >> Relying on the wrap bit to stay valid once initialized when the controller also >> writes to this byte seems undesirable since we can easily know what the value >> should be. >> >> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com> >> --- >> drivers/net/ethernet/freescale/fec_main.c | 38 +++++++++---------------------- >> 1 file changed, 11 insertions(+), 27 deletions(-) >> >> diff --git a/drivers/net/ethernet/freescale/fec_main.c >> b/drivers/net/ethernet/freescale/fec_main.c >> index 791f385..6ceb5f9 100644 >> --- a/drivers/net/ethernet/freescale/fec_main.c >> +++ b/drivers/net/ethernet/freescale/fec_main.c >> @@ -340,9 +340,8 @@ fec_enet_txq_submit_frag_skb(struct >> fec_enet_priv_tx_q *txq, >> bdp = fec_enet_get_nextdesc(bdp, &txq->bd); >> ebdp = (struct bufdesc_ex *)bdp; >> >> - status = fec16_to_cpu(bdp->cbd_sc); >> - status &= ~BD_ENET_TX_STATS; >> - status |= (BD_ENET_TX_TC | BD_ENET_TX_READY); >> + status = BD_ENET_TX_TC | BD_ENET_TX_READY | >> + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); >> frag_len = skb_shinfo(skb)->frags[frag].size; >> >> /* Handle the last BD specially */ >> @@ -436,8 +435,6 @@ static int fec_enet_txq_submit_skb(struct >> fec_enet_priv_tx_q *txq, >> /* Fill in a Tx ring entry */ >> bdp = txq->bd.cur; >> last_bdp = bdp; >> - status = fec16_to_cpu(bdp->cbd_sc); >> - status &= ~BD_ENET_TX_STATS; >> >> /* Set buffer length and buffer pointer */ >> bufaddr = skb->data; >> @@ -462,6 +459,8 @@ static int fec_enet_txq_submit_skb(struct >> fec_enet_priv_tx_q *txq, >> return NETDEV_TX_OK; >> } >> >> + status = BD_ENET_TX_TC | BD_ENET_TX_READY | >> + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); >> if (nr_frags) { >> last_bdp = fec_enet_txq_submit_frag_skb(txq, skb, ndev); >> if (IS_ERR(last_bdp)) { >> @@ -512,7 +511,6 @@ static int fec_enet_txq_submit_skb(struct >> fec_enet_priv_tx_q *txq, >> /* Send it on its way. Tell FEC it's ready, interrupt when done, >> * it's the last BD of the frame, and to put the CRC on the end. >> */ >> - status |= (BD_ENET_TX_READY | BD_ENET_TX_TC); > > This is completely error. We have to prepare all BDs for frag skb, and then enable "READY" and "TC" bit for the first BD, otherwise uDMA copy un-correct data to fifo. > I don't follow. Please read patch again. Thanks Troy
From: Troy Kisky <troy.kisky@boundarydevices.com> Sent: Saturday, March 05, 2016 12:08 AM > To: Fugang Duan <fugang.duan@nxp.com>; netdev@vger.kernel.org; > davem@davemloft.net; b38611@freescale.com > Cc: fabio.estevam@freescale.com; l.stach@pengutronix.de; andrew@lunn.ch; > tremyfr@gmail.com; linux@arm.linux.org.uk; linux-arm- > kernel@lists.infradead.org; laci@boundarydevices.com; shawnguo@kernel.org; > johannes@sipsolutions.net; stillcompiling@gmail.com; > sergei.shtylyov@cogentembedded.com; arnd@arndb.de > Subject: Re: [PATCH net-next V2 07/16] net: fec: set cbd_sc without relying on > previous value > > On 3/4/2016 2:29 AM, Fugang Duan wrote: > > From: Troy Kisky <troy.kisky@boundarydevices.com> Sent: Thursday, > > February 25, 2016 8:37 AM > >> To: netdev@vger.kernel.org; davem@davemloft.net; > b38611@freescale.com > >> Cc: fabio.estevam@freescale.com; l.stach@pengutronix.de; > >> andrew@lunn.ch; tremyfr@gmail.com; linux@arm.linux.org.uk; linux-arm- > >> kernel@lists.infradead.org; laci@boundarydevices.com; > >> shawnguo@kernel.org; johannes@sipsolutions.net; > >> stillcompiling@gmail.com; sergei.shtylyov@cogentembedded.com; > >> arnd@arndb.de; Troy Kisky <troy.kisky@boundarydevices.com> > >> Subject: [PATCH net-next V2 07/16] net: fec: set cbd_sc without > >> relying on previous value > >> > >> Relying on the wrap bit to stay valid once initialized when the > >> controller also writes to this byte seems undesirable since we can > >> easily know what the value should be. > >> > >> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com> > >> --- > >> drivers/net/ethernet/freescale/fec_main.c | 38 > >> +++++++++---------------------- > >> 1 file changed, 11 insertions(+), 27 deletions(-) > >> > >> diff --git a/drivers/net/ethernet/freescale/fec_main.c > >> b/drivers/net/ethernet/freescale/fec_main.c > >> index 791f385..6ceb5f9 100644 > >> --- a/drivers/net/ethernet/freescale/fec_main.c > >> +++ b/drivers/net/ethernet/freescale/fec_main.c > >> @@ -340,9 +340,8 @@ fec_enet_txq_submit_frag_skb(struct > >> fec_enet_priv_tx_q *txq, > >> bdp = fec_enet_get_nextdesc(bdp, &txq->bd); > >> ebdp = (struct bufdesc_ex *)bdp; > >> > >> - status = fec16_to_cpu(bdp->cbd_sc); > >> - status &= ~BD_ENET_TX_STATS; > >> - status |= (BD_ENET_TX_TC | BD_ENET_TX_READY); > >> + status = BD_ENET_TX_TC | BD_ENET_TX_READY | > >> + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); > >> frag_len = skb_shinfo(skb)->frags[frag].size; > >> > >> /* Handle the last BD specially */ @@ -436,8 +435,6 @@ static > int > >> fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq, > >> /* Fill in a Tx ring entry */ > >> bdp = txq->bd.cur; > >> last_bdp = bdp; > >> - status = fec16_to_cpu(bdp->cbd_sc); > >> - status &= ~BD_ENET_TX_STATS; > >> > >> /* Set buffer length and buffer pointer */ > >> bufaddr = skb->data; > >> @@ -462,6 +459,8 @@ static int fec_enet_txq_submit_skb(struct > >> fec_enet_priv_tx_q *txq, > >> return NETDEV_TX_OK; > >> } > >> > >> + status = BD_ENET_TX_TC | BD_ENET_TX_READY | > >> + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); > >> if (nr_frags) { > >> last_bdp = fec_enet_txq_submit_frag_skb(txq, skb, ndev); > >> if (IS_ERR(last_bdp)) { > >> @@ -512,7 +511,6 @@ static int fec_enet_txq_submit_skb(struct > >> fec_enet_priv_tx_q *txq, > >> /* Send it on its way. Tell FEC it's ready, interrupt when done, > >> * it's the last BD of the frame, and to put the CRC on the end. > >> */ > >> - status |= (BD_ENET_TX_READY | BD_ENET_TX_TC); > > > > This is completely error. We have to prepare all BDs for frag skb, and then > enable "READY" and "TC" bit for the first BD, otherwise uDMA copy un-correct > data to fifo. > > > > > > > I don't follow. Please read patch again. > Understand, sorry, I take one mistake. The patch is fine for me.
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 791f385..6ceb5f9 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -340,9 +340,8 @@ fec_enet_txq_submit_frag_skb(struct fec_enet_priv_tx_q *txq, bdp = fec_enet_get_nextdesc(bdp, &txq->bd); ebdp = (struct bufdesc_ex *)bdp; - status = fec16_to_cpu(bdp->cbd_sc); - status &= ~BD_ENET_TX_STATS; - status |= (BD_ENET_TX_TC | BD_ENET_TX_READY); + status = BD_ENET_TX_TC | BD_ENET_TX_READY | + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); frag_len = skb_shinfo(skb)->frags[frag].size; /* Handle the last BD specially */ @@ -436,8 +435,6 @@ static int fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq, /* Fill in a Tx ring entry */ bdp = txq->bd.cur; last_bdp = bdp; - status = fec16_to_cpu(bdp->cbd_sc); - status &= ~BD_ENET_TX_STATS; /* Set buffer length and buffer pointer */ bufaddr = skb->data; @@ -462,6 +459,8 @@ static int fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq, return NETDEV_TX_OK; } + status = BD_ENET_TX_TC | BD_ENET_TX_READY | + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); if (nr_frags) { last_bdp = fec_enet_txq_submit_frag_skb(txq, skb, ndev); if (IS_ERR(last_bdp)) { @@ -512,7 +511,6 @@ static int fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq, /* Send it on its way. Tell FEC it's ready, interrupt when done, * it's the last BD of the frame, and to put the CRC on the end. */ - status |= (BD_ENET_TX_READY | BD_ENET_TX_TC); bdp->cbd_sc = cpu_to_fec16(status); /* If this was the last BD in the ring, start at the beginning again. */ @@ -544,11 +542,6 @@ fec_enet_txq_put_data_tso(struct fec_enet_priv_tx_q *txq, struct sk_buff *skb, unsigned int estatus = 0; dma_addr_t addr; - status = fec16_to_cpu(bdp->cbd_sc); - status &= ~BD_ENET_TX_STATS; - - status |= (BD_ENET_TX_TC | BD_ENET_TX_READY); - if (((unsigned long) data) & fep->tx_align || fep->quirks & FEC_QUIRK_SWAP_FRAME) { memcpy(txq->tx_bounce[index], data, size); @@ -578,15 +571,16 @@ fec_enet_txq_put_data_tso(struct fec_enet_priv_tx_q *txq, struct sk_buff *skb, ebdp->cbd_esc = cpu_to_fec32(estatus); } + status = BD_ENET_TX_TC | BD_ENET_TX_READY | + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0); /* Handle the last BD specially */ if (last_tcp) - status |= (BD_ENET_TX_LAST | BD_ENET_TX_TC); + status |= BD_ENET_TX_LAST; if (is_last) { status |= BD_ENET_TX_INTR; if (fep->bufdesc_ex) ebdp->cbd_esc |= cpu_to_fec32(BD_ENET_TX_INT); } - bdp->cbd_sc = cpu_to_fec16(status); return 0; @@ -602,13 +596,8 @@ fec_enet_txq_put_hdr_tso(struct fec_enet_priv_tx_q *txq, struct bufdesc_ex *ebdp = container_of(bdp, struct bufdesc_ex, desc); void *bufaddr; unsigned long dmabuf; - unsigned short status; unsigned int estatus = 0; - status = fec16_to_cpu(bdp->cbd_sc); - status &= ~BD_ENET_TX_STATS; - status |= (BD_ENET_TX_TC | BD_ENET_TX_READY); - bufaddr = txq->tso_hdrs + index * TSO_HEADER_SIZE; dmabuf = txq->tso_hdrs_dma + index * TSO_HEADER_SIZE; if (((unsigned long)bufaddr) & fep->tx_align || @@ -641,8 +630,8 @@ fec_enet_txq_put_hdr_tso(struct fec_enet_priv_tx_q *txq, ebdp->cbd_esc = cpu_to_fec32(estatus); } - bdp->cbd_sc = cpu_to_fec16(status); - + bdp->cbd_sc = cpu_to_fec16(BD_ENET_TX_TC | BD_ENET_TX_READY | + ((bdp == txq->bd.last) ? BD_SC_WRAP : 0)); return 0; } @@ -1453,12 +1442,6 @@ static int fec_rxq(struct net_device *ndev, struct fec_enet_private *fep, } rx_processing_done: - /* Clear the status flags for this buffer */ - status &= ~BD_ENET_RX_STATS; - - /* Mark the buffer empty */ - status |= BD_ENET_RX_EMPTY; - if (fep->bufdesc_ex) { struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp; @@ -1470,7 +1453,8 @@ rx_processing_done: * performed before transferring ownership. */ wmb(); - bdp->cbd_sc = cpu_to_fec16(status); + bdp->cbd_sc = cpu_to_fec16(BD_ENET_RX_EMPTY | + ((bdp == rxq->bd.last) ? BD_SC_WRAP : 0)); /* Update BD pointer to next entry */ bdp = fec_enet_get_nextdesc(bdp, &rxq->bd);
Relying on the wrap bit to stay valid once initialized when the controller also writes to this byte seems undesirable since we can easily know what the value should be. Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com> --- drivers/net/ethernet/freescale/fec_main.c | 38 +++++++++---------------------- 1 file changed, 11 insertions(+), 27 deletions(-)