| Message ID | 1410801177-15872-5-git-send-email-Frank.Li@freescale.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
From: <Frank.Li@freescale.com> Date: Tue, 16 Sep 2014 01:12:57 +0800 > @@ -111,6 +111,13 @@ static void fec_enet_itr_coal_init(struct net_device *ndev); > * independent rings > */ > #define FEC_QUIRK_HAS_AVB (1 << 8) > +/* > + * There is a TDAR race condition for mutliQ when the software sets TDAR > + * and the UDMA clears TDAR simultaneously or in a small window (2-4 cycles). > + * This will cause the udma_tx and udma_tx_arbiter state machines to hang. > + * The issue exist at i.MX6SX enet IP. > + */ > +#define FEC_QUIRK_TKT210582 (1 << 9) Networking comments should be of the form: /* Like * this. */ > /* Trigger transmission start */ > - writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); > + if (!(id_entry->driver_data & FEC_QUIRK_TKT210582) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue))) > + writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); This conditional is not indented properly, see my feedback for patch #2.
On Tue, Sep 16, 2014 at 01:12:57AM +0800, Frank.Li@freescale.com wrote: > From: Fugang Duan <B38611@freescale.com> > > When enable three queues on imx6sx enet, and then do tx performance > test with iperf tool, after some time running, tx hang. > > Found that: > If uDMA is running, software set TDAR may cause tx hang. > If uDMA is in idle, software set TDAR don't cause tx hang. > > There is a TDAR race condition for mutliQ when the software sets TDAR > and the UDMA clears TDAR simultaneously or in a small window (2-4 cycles). > This will cause the udma_tx and udma_tx_arbiter state machines to hang. > The issue exist at i.MX6SX enet IP. > > So, the Workaround is checking TDAR status four time, if TDAR cleared by > hardware and then write TDAR, otherwise don't set TDAR. > > The patch is only one Workaround for the issue TKT210582. > > Signed-off-by: Fugang Duan <B38611@freescale.com> > Signed-off-by: Frank Li <Frank.Li@freescale.com> > --- > drivers/net/ethernet/freescale/fec_main.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c > index 524ddbe..452e576 100644 > --- a/drivers/net/ethernet/freescale/fec_main.c > +++ b/drivers/net/ethernet/freescale/fec_main.c > @@ -111,6 +111,13 @@ static void fec_enet_itr_coal_init(struct net_device *ndev); > * independent rings > */ > #define FEC_QUIRK_HAS_AVB (1 << 8) > +/* > + * There is a TDAR race condition for mutliQ when the software sets TDAR > + * and the UDMA clears TDAR simultaneously or in a small window (2-4 cycles). > + * This will cause the udma_tx and udma_tx_arbiter state machines to hang. > + * The issue exist at i.MX6SX enet IP. > + */ > +#define FEC_QUIRK_TKT210582 (1 << 9) I think TKTxxx number is used by Freescale design team to track issues internally, and there should be a corresponding errata number like ERRxxx which should be accessible by external people in errata document? Shawn > > static struct platform_device_id fec_devtype[] = { > { > @@ -139,7 +146,7 @@ static struct platform_device_id fec_devtype[] = { > .driver_data = FEC_QUIRK_ENET_MAC | FEC_QUIRK_HAS_GBIT | > FEC_QUIRK_HAS_BUFDESC_EX | FEC_QUIRK_HAS_CSUM | > FEC_QUIRK_HAS_VLAN | FEC_QUIRK_ERR006358 | > - FEC_QUIRK_HAS_AVB, > + FEC_QUIRK_HAS_AVB | FEC_QUIRK_TKT210582, > }, { > /* sentinel */ > } > @@ -709,6 +716,8 @@ static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq, > struct tso_t tso; > unsigned int index = 0; > int ret; > + const struct platform_device_id *id_entry = > + platform_get_device_id(fep->pdev); > > if (tso_count_descs(skb) >= fec_enet_get_free_txdesc_num(fep, txq)) { > dev_kfree_skb_any(skb); > @@ -770,7 +779,12 @@ static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq, > txq->cur_tx = bdp; > > /* Trigger transmission start */ > - writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); > + if (!(id_entry->driver_data & FEC_QUIRK_TKT210582) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || > + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue))) > + writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); > > return 0; > > -- > 1.9.1 >
From: Shawn Guo <shawn.guo@linaro.org> Sent: Tuesday, September 16, 2014 8:52 AM >To: Li Frank-B20596 >Cc: Duan Fugang-B38611; davem@davemloft.net; netdev@vger.kernel.org; >lznuaa@gmail.com; linux-arm-kernel@lists.infradead.org >Subject: Re: [Patch net-next 4/4] net: fec: Workaround for imx6sx enet tx >hang when enable three queues > >On Tue, Sep 16, 2014 at 01:12:57AM +0800, Frank.Li@freescale.com wrote: >> From: Fugang Duan <B38611@freescale.com> >> >> When enable three queues on imx6sx enet, and then do tx performance >> test with iperf tool, after some time running, tx hang. >> >> Found that: >> If uDMA is running, software set TDAR may cause tx hang. >> If uDMA is in idle, software set TDAR don't cause tx hang. >> >> There is a TDAR race condition for mutliQ when the software sets TDAR >> and the UDMA clears TDAR simultaneously or in a small window (2-4 >cycles). >> This will cause the udma_tx and udma_tx_arbiter state machines to hang. >> The issue exist at i.MX6SX enet IP. >> >> So, the Workaround is checking TDAR status four time, if TDAR cleared >> by hardware and then write TDAR, otherwise don't set TDAR. >> >> The patch is only one Workaround for the issue TKT210582. >> >> Signed-off-by: Fugang Duan <B38611@freescale.com> >> Signed-off-by: Frank Li <Frank.Li@freescale.com> >> --- >> drivers/net/ethernet/freescale/fec_main.c | 18 ++++++++++++++++-- >> 1 file changed, 16 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/net/ethernet/freescale/fec_main.c >> b/drivers/net/ethernet/freescale/fec_main.c >> index 524ddbe..452e576 100644 >> --- a/drivers/net/ethernet/freescale/fec_main.c >> +++ b/drivers/net/ethernet/freescale/fec_main.c >> @@ -111,6 +111,13 @@ static void fec_enet_itr_coal_init(struct >net_device *ndev); >> * independent rings >> */ >> #define FEC_QUIRK_HAS_AVB (1 << 8) >> +/* >> + * There is a TDAR race condition for mutliQ when the software sets >> +TDAR >> + * and the UDMA clears TDAR simultaneously or in a small window (2-4 >cycles). >> + * This will cause the udma_tx and udma_tx_arbiter state machines to >hang. >> + * The issue exist at i.MX6SX enet IP. >> + */ >> +#define FEC_QUIRK_TKT210582 (1 << 9) > >I think TKTxxx number is used by Freescale design team to track issues >internally, and there should be a corresponding errata number like ERRxxx >which should be accessible by external people in errata document? > >Shawn The issue ticket is: TDAR race condition for mutliQ - Errata: ERR007885 > >> >> static struct platform_device_id fec_devtype[] = { >> { >> @@ -139,7 +146,7 @@ static struct platform_device_id fec_devtype[] = { >> .driver_data = FEC_QUIRK_ENET_MAC | FEC_QUIRK_HAS_GBIT | >> FEC_QUIRK_HAS_BUFDESC_EX | FEC_QUIRK_HAS_CSUM | >> FEC_QUIRK_HAS_VLAN | FEC_QUIRK_ERR006358 | >> - FEC_QUIRK_HAS_AVB, >> + FEC_QUIRK_HAS_AVB | FEC_QUIRK_TKT210582, >> }, { >> /* sentinel */ >> } >> @@ -709,6 +716,8 @@ static int fec_enet_txq_submit_tso(struct >fec_enet_priv_tx_q *txq, >> struct tso_t tso; >> unsigned int index = 0; >> int ret; >> + const struct platform_device_id *id_entry = >> + platform_get_device_id(fep->pdev); >> >> if (tso_count_descs(skb) >= fec_enet_get_free_txdesc_num(fep, txq)) >{ >> dev_kfree_skb_any(skb); >> @@ -770,7 +779,12 @@ static int fec_enet_txq_submit_tso(struct >fec_enet_priv_tx_q *txq, >> txq->cur_tx = bdp; >> >> /* Trigger transmission start */ >> - writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); >> + if (!(id_entry->driver_data & FEC_QUIRK_TKT210582) || >> + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || >> + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || >> + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || >> + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue))) >> + writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); >> >> return 0; >> >> -- >> 1.9.1 >>
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 524ddbe..452e576 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -111,6 +111,13 @@ static void fec_enet_itr_coal_init(struct net_device *ndev); * independent rings */ #define FEC_QUIRK_HAS_AVB (1 << 8) +/* + * There is a TDAR race condition for mutliQ when the software sets TDAR + * and the UDMA clears TDAR simultaneously or in a small window (2-4 cycles). + * This will cause the udma_tx and udma_tx_arbiter state machines to hang. + * The issue exist at i.MX6SX enet IP. + */ +#define FEC_QUIRK_TKT210582 (1 << 9) static struct platform_device_id fec_devtype[] = { { @@ -139,7 +146,7 @@ static struct platform_device_id fec_devtype[] = { .driver_data = FEC_QUIRK_ENET_MAC | FEC_QUIRK_HAS_GBIT | FEC_QUIRK_HAS_BUFDESC_EX | FEC_QUIRK_HAS_CSUM | FEC_QUIRK_HAS_VLAN | FEC_QUIRK_ERR006358 | - FEC_QUIRK_HAS_AVB, + FEC_QUIRK_HAS_AVB | FEC_QUIRK_TKT210582, }, { /* sentinel */ } @@ -709,6 +716,8 @@ static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq, struct tso_t tso; unsigned int index = 0; int ret; + const struct platform_device_id *id_entry = + platform_get_device_id(fep->pdev); if (tso_count_descs(skb) >= fec_enet_get_free_txdesc_num(fep, txq)) { dev_kfree_skb_any(skb); @@ -770,7 +779,12 @@ static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq, txq->cur_tx = bdp; /* Trigger transmission start */ - writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); + if (!(id_entry->driver_data & FEC_QUIRK_TKT210582) || + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) || + !readl(fep->hwp + FEC_X_DES_ACTIVE(queue))) + writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue)); return 0;