[PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Joakim Zhang]

This patch set intends to fix TX bandwidth fluctuations, any feedback would be appreciated.

---
ChangeLogs:
	V1: remove RFC tag, RFC discussions please turn to below:
	    https://lore.kernel.org/lkml/YK0Ce5YxR2WYbrAo@lunn.ch/T/
	V2: change functions to be static in this patch set. And add the
	t-b tag.

Fugang Duan (1):
  net: fec: add ndo_select_queue to fix TX bandwidth fluctuations

Joakim Zhang (1):
  net: fec: add FEC_QUIRK_HAS_MULTI_QUEUES represents i.MX6SX ENET IP

 drivers/net/ethernet/freescale/fec.h      |  5 +++
 drivers/net/ethernet/freescale/fec_main.c | 43 ++++++++++++++++++++---
 2 files changed, 43 insertions(+), 5 deletions(-)

-- 
2.17.1

[PATCH V2 1/2] net: fec: add FEC_QUIRK_HAS_MULTI_QUEUES represents i.MX6SX ENET IP

[Joakim Zhang]

Frieder Schrempf reported a TX throuthput issue [1], it happens quite often
that the measured bandwidth in TX direction drops from its expected/nominal
value to something like ~50% (for 100M) or ~67% (for 1G) connections.

[1] https://lore.kernel.org/linux-arm-kernel/421cc86c-b66f-b372-32f7-21e59f9a98bc@kontron.de/

The issue becomes clear after digging into it, Net core would select
queues when transmitting packets. Since FEC have not impletemented
ndo_select_queue callback yet, so it will call netdev_pick_tx to select
queues randomly.

For i.MX6SX ENET IP with AVB support, driver default enables this
feature. According to the setting of QOS/RCMRn/DMAnCFG registers, AVB
configured to Credit-based scheme, 50% bandwidth of each queue 1&2.

With below tests let me think more:
1) With FEC_QUIRK_HAS_AVB quirk, can reproduce TX bandwidth fluctuations issue.
2) Without FEC_QUIRK_HAS_AVB quirk, can't reproduce TX bandwidth fluctuations issue.

The related difference with or w/o FEC_QUIRK_HAS_AVB quirk is that, whether we
program FTYPE field of TxBD or not. As I describe above, AVB feature is
enabled by default. With FEC_QUIRK_HAS_AVB quirk, frames in queue 0
marked as non-AVB, and frames in queue 1&2 marked as AVB Class A&B. It's
unreasonable if frames in queue 1&2 are not required to be time-sensitive.
So when Net core select tx queues ramdomly, Credit-based scheme would work
and lead to TX bandwidth fluctuated. On the other hand, w/o
FEC_QUIRK_HAS_AVB quirk, frames in queue 1&2 are all marked as non-AVB, so
Credit-based scheme would not work.

Till now, how can we fix this TX throughput issue? Yes, please remove
FEC_QUIRK_HAS_AVB quirk if you suffer it from time-nonsensitive networking.
However, this quirk is used to indicate i.MX6SX, other setting depends
on it. So this patch adds a new quirk FEC_QUIRK_HAS_MULTI_QUEUES to
represent i.MX6SX, it is safe for us remove FEC_QUIRK_HAS_AVB quirk
now.

FEC_QUIRK_HAS_AVB quirk is set by default in the driver, and users may
not know much about driver details, they would waste effort to find the
root cause, that is not we want. The following patch is a implementation
to fix it and users don't need to modify the driver.

Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reported-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/ethernet/freescale/fec.h      |  5 +++++
 drivers/net/ethernet/freescale/fec_main.c | 11 ++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 0602d5d5d2ee..2e002e4b4b4a 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -467,6 +467,11 @@ struct bufdesc_ex {
  */
 #define FEC_QUIRK_NO_HARD_RESET		(1 << 18)
 
+/* i.MX6SX ENET IP supports multiple queues (3 queues), use this quirk to
+ * represents this ENET IP.
+ */
+#define FEC_QUIRK_HAS_MULTI_QUEUES	(1 << 19)
+
 struct bufdesc_prop {
 	int qid;
 	/* Address of Rx and Tx buffers */
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index ad82cffc6f3f..98cd38379275 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -122,7 +122,7 @@ static const struct fec_devinfo fec_imx6x_info = {
 		  FEC_QUIRK_HAS_VLAN | FEC_QUIRK_HAS_AVB |
 		  FEC_QUIRK_ERR007885 | FEC_QUIRK_BUG_CAPTURE |
 		  FEC_QUIRK_HAS_RACC | FEC_QUIRK_HAS_COALESCE |
-		  FEC_QUIRK_CLEAR_SETUP_MII,
+		  FEC_QUIRK_CLEAR_SETUP_MII | FEC_QUIRK_HAS_MULTI_QUEUES,
 };
 
 static const struct fec_devinfo fec_imx6ul_info = {
@@ -421,6 +421,7 @@ fec_enet_txq_submit_frag_skb(struct fec_enet_priv_tx_q *txq,
 				estatus |= FEC_TX_BD_FTYPE(txq->bd.qid);
 			if (skb->ip_summed == CHECKSUM_PARTIAL)
 				estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;
+
 			ebdp->cbd_bdu = 0;
 			ebdp->cbd_esc = cpu_to_fec32(estatus);
 		}
@@ -954,7 +955,7 @@ fec_restart(struct net_device *ndev)
 	 * For i.MX6SX SOC, enet use AXI bus, we use disable MAC
 	 * instead of reset MAC itself.
 	 */
-	if (fep->quirks & FEC_QUIRK_HAS_AVB ||
+	if (fep->quirks & FEC_QUIRK_HAS_MULTI_QUEUES ||
 	    ((fep->quirks & FEC_QUIRK_NO_HARD_RESET) && fep->link)) {
 		writel(0, fep->hwp + FEC_ECNTRL);
 	} else {
@@ -1165,7 +1166,7 @@ fec_stop(struct net_device *ndev)
 	 * instead of reset MAC itself.
 	 */
 	if (!(fep->wol_flag & FEC_WOL_FLAG_SLEEP_ON)) {
-		if (fep->quirks & FEC_QUIRK_HAS_AVB) {
+		if (fep->quirks & FEC_QUIRK_HAS_MULTI_QUEUES) {
 			writel(0, fep->hwp + FEC_ECNTRL);
 		} else {
 			writel(1, fep->hwp + FEC_ECNTRL);
@@ -2570,7 +2571,7 @@ static void fec_enet_itr_coal_set(struct net_device *ndev)
 
 	writel(tx_itr, fep->hwp + FEC_TXIC0);
 	writel(rx_itr, fep->hwp + FEC_RXIC0);
-	if (fep->quirks & FEC_QUIRK_HAS_AVB) {
+	if (fep->quirks & FEC_QUIRK_HAS_MULTI_QUEUES) {
 		writel(tx_itr, fep->hwp + FEC_TXIC1);
 		writel(rx_itr, fep->hwp + FEC_RXIC1);
 		writel(tx_itr, fep->hwp + FEC_TXIC2);
@@ -3371,7 +3372,7 @@ static int fec_enet_init(struct net_device *ndev)
 		fep->csum_flags |= FLAG_RX_CSUM_ENABLED;
 	}
 
-	if (fep->quirks & FEC_QUIRK_HAS_AVB) {
+	if (fep->quirks & FEC_QUIRK_HAS_MULTI_QUEUES) {
 		fep->tx_align = 0;
 		fep->rx_align = 0x3f;
 	}
-- 
2.17.1

[PATCH V2 2/2] net: fec: add ndo_select_queue to fix TX bandwidth fluctuations

[Joakim Zhang]

From: Fugang Duan <fugang.duan@nxp.com>

As we know that AVB is enabled by default, and the ENET IP design is
queue 0 for best effort, queue 1&2 for AVB Class A&B. Bandwidth of each
queue 1&2 set in driver is 50%, TX bandwidth fluctuated when selecting
tx queues randomly with FEC_QUIRK_HAS_AVB quirk available.

This patch adds ndo_select_queue callback to select queues for
transmitting to fix this issue. It will always return queue 0 if this is
not a vlan packet, and return queue 1 or 2 based on priority of vlan
packet.

You may complain that in fact we only use single queue for trasmitting
if we are not targeted to VLAN. Yes, but seems we have no choice, since
AVB is enabled when the driver probed, we can't switch this feature
dynamicly. After compare multiple queues to single queue, TX throughput
almost no improvement.

One way we can implemet is to configure the driver to multiple queues
with Round-robin scheme by default. Then add ndo_setup_tc callback to
enable/disable AVB feature for users. Unfortunately, ENET AVB IP seems
not follow the standard 802.1Qav spec. We only can program
DMAnCFG[IDLE_SLOPE] field to calculate bandwidth fraction. And idle
slope is restricted to certain valus (a total of 19). It's far away from
CBS QDisc implemented in Linux TC framework. If you strongly suggest to do
this, I think we only can support limited numbers of bandwidth and reject
others, but it's really urgly and wried.

With this patch, VLAN tagged packets route to queue 0/1/2 based on vlan
priority; VLAN untagged packets route to queue 0.

Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reported-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/ethernet/freescale/fec_main.c | 32 +++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 98cd38379275..00d3fa8ed3a7 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -76,6 +76,8 @@ static void fec_enet_itr_coal_init(struct net_device *ndev);
 
 #define DRIVER_NAME	"fec"
 
+static const u16 fec_enet_vlan_pri_to_queue[8] = {0, 0, 1, 1, 1, 2, 2, 2};
+
 /* Pause frame feild and FIFO threshold */
 #define FEC_ENET_FCE	(1 << 5)
 #define FEC_ENET_RSEM_V	0x84
@@ -3240,10 +3242,40 @@ static int fec_set_features(struct net_device *netdev,
 	return 0;
 }
 
+static u16 fec_enet_get_raw_vlan_tci(struct sk_buff *skb)
+{
+	struct vlan_ethhdr *vhdr;
+	unsigned short vlan_TCI = 0;
+
+	if (skb->protocol == ntohs(ETH_P_ALL)) {
+		vhdr = (struct vlan_ethhdr *)(skb->data);
+		vlan_TCI = ntohs(vhdr->h_vlan_TCI);
+	}
+
+	return vlan_TCI;
+}
+
+static u16 fec_enet_select_queue(struct net_device *ndev, struct sk_buff *skb,
+				 struct net_device *sb_dev)
+{
+	struct fec_enet_private *fep = netdev_priv(ndev);
+	u16 vlan_tag;
+
+	if (!(fep->quirks & FEC_QUIRK_HAS_AVB))
+		return netdev_pick_tx(ndev, skb, NULL);
+
+	vlan_tag = fec_enet_get_raw_vlan_tci(skb);
+	if (!vlan_tag)
+		return vlan_tag;
+
+	return fec_enet_vlan_pri_to_queue[vlan_tag >> 13];
+}
+
 static const struct net_device_ops fec_netdev_ops = {
 	.ndo_open		= fec_enet_open,
 	.ndo_stop		= fec_enet_close,
 	.ndo_start_xmit		= fec_enet_start_xmit,
+	.ndo_select_queue       = fec_enet_select_queue,
 	.ndo_set_rx_mode	= set_multicast_list,
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_tx_timeout		= fec_timeout,
-- 
2.17.1

Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[David Miller]

From: Joakim Zhang <qiangqing.zhang@nxp.com>
Date: Fri, 11 Jun 2021 17:50:03 +0800

> This patch set intends to fix TX bandwidth fluctuations, any feedback would be appreciated.
> 
> ---
> ChangeLogs:
> 	V1: remove RFC tag, RFC discussions please turn to below:
> 	    https://lore.kernel.org/lkml/YK0Ce5YxR2WYbrAo@lunn.ch/T/
> 	V2: change functions to be static in this patch set. And add the
> 	t-b tag.

Please fix these warnings in patch #2:

https://patchwork.hopto.org/static/nipa/498729/12315211/build_allmodconfig_warn/summary

Thank you.

RE: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Joakim Zhang]

Hi David,

> -----Original Message-----
> From: David Miller <davem@davemloft.net>
> Sent: 2021年6月12日 4:25
> To: Joakim Zhang <qiangqing.zhang@nxp.com>
> Cc: kuba@kernel.org; frieder.schrempf@kontron.de; andrew@lunn.ch;
> netdev@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations
> 
> From: Joakim Zhang <qiangqing.zhang@nxp.com>
> Date: Fri, 11 Jun 2021 17:50:03 +0800
> 
> > This patch set intends to fix TX bandwidth fluctuations, any feedback would
> be appreciated.
> >
> > ---
> > ChangeLogs:
> > 	V1: remove RFC tag, RFC discussions please turn to below:
> >
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.ker
> nel.org%2Flkml%2FYK0Ce5YxR2WYbrAo%40lunn.ch%2FT%2F&amp;data=04%7
> C01%7Cqiangqing.zhang%40nxp.com%7C45b786c85a294b3ea9ec08d92d1709
> 0c%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637590399225645
> 759%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzI
> iLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=CFeL4rNWqNs4Xc
> 2NqtBiQxex4%2FXAUhEXWQreftFhnY4%3D&amp;reserved=0
> > 	V2: change functions to be static in this patch set. And add the
> > 	t-b tag.
> 
> Please fix these warnings in patch #2:
> 
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchw
> ork.hopto.org%2Fstatic%2Fnipa%2F498729%2F12315211%2Fbuild_allmodconfi
> g_warn%2Fsummary&amp;data=04%7C01%7Cqiangqing.zhang%40nxp.com%
> 7C45b786c85a294b3ea9ec08d92d17090c%7C686ea1d3bc2b4c6fa92cd99c5c30
> 1635%7C0%7C0%7C637590399225645759%7CUnknown%7CTWFpbGZsb3d8ey
> JWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%
> 7C1000&amp;sdata=eb4Ujx2FKOnu5M41j1RnPLCBoEoGfQiCO%2BO5MzIsXyE
> %3D&amp;reserved=0

I can't reproduce these warnings with " make ARCH=arm64 allmodconfig", could you please show me the command you used? Thanks.

Best Regards,
Joakim Zhang
> Thank you.

Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Andrew Lunn]

> I can't reproduce these warnings with " make ARCH=arm64 allmodconfig", could you please show me the command you used? Thanks.

Try adding W=1

    Andrew

RE: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Joakim Zhang]

Hi Andrew, David,

> -----Original Message-----
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: 2021年6月15日 20:28
> To: Joakim Zhang <qiangqing.zhang@nxp.com>
> Cc: David Miller <davem@davemloft.net>; kuba@kernel.org;
> frieder.schrempf@kontron.de; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations
> 
> > I can't reproduce these warnings with " make ARCH=arm64 allmodconfig",
> could you please show me the command you used? Thanks.
> 
> Try adding W=1

Thanks.

I try below build options, also can't reproduce this issue, so really don't know how to fix it.

make ARCH=arm64 distclean
make ARCH=arm64 allmodconfig
make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1 / make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=2 / make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=3

I saw many unrelated warnings...

Best Regards,
Joakim Zhang
>     Andrew

Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Andrew Lunn]

> I try below build options, also can't reproduce this issue, so really don't know how to fix it.
> 
> make ARCH=arm64 distclean
> make ARCH=arm64 allmodconfig
> make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1 / make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=2 / make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=3
> 
> I saw many unrelated warnings...

Then it could be sparse. Install sparse and use C=1.

     Andrew

RE: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Joakim Zhang]

Hi Andrew,

> -----Original Message-----
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: 2021年6月16日 21:06
> To: Joakim Zhang <qiangqing.zhang@nxp.com>
> Cc: David Miller <davem@davemloft.net>; kuba@kernel.org;
> frieder.schrempf@kontron.de; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations
> 
> > I try below build options, also can't reproduce this issue, so really don't know
> how to fix it.
> >
> > make ARCH=arm64 distclean
> > make ARCH=arm64 allmodconfig
> > make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1 / make -j8
> ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=2 / make -j8
> ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=3
> >
> > I saw many unrelated warnings...
> 
> Then it could be sparse. Install sparse and use C=1.

After applying the patch #2, I tried to use C=1 yesterday, I double check it today, still no warnings. Anything I missing?

$ make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1,C=1
  CALL    scripts/atomic/check-atomics.sh
  CALL    scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  CHK     kernel/kheaders_data.tar.xz
  CC [M]  drivers/net/ethernet/freescale/fec_main.o
  LD [M]  drivers/net/ethernet/freescale/fec.o
  MODPOST modules-only.symvers
  GEN     Module.symvers
  CC [M]  drivers/net/ethernet/freescale/fec.mod.o
  LD [M]  drivers/net/ethernet/freescale/fec.ko

Best Regards,
Joakim Zhang
>      Andrew

Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Andrew Lunn]

On Thu, Jun 17, 2021 at 11:40:58AM +0000, Joakim Zhang wrote:
> 
> Hi Andrew,
> 
> > -----Original Message-----
> > From: Andrew Lunn <andrew@lunn.ch>
> > Sent: 2021年6月16日 21:06
> > To: Joakim Zhang <qiangqing.zhang@nxp.com>
> > Cc: David Miller <davem@davemloft.net>; kuba@kernel.org;
> > frieder.schrempf@kontron.de; netdev@vger.kernel.org;
> > linux-kernel@vger.kernel.org
> > Subject: Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations
> > 
> > > I try below build options, also can't reproduce this issue, so really don't know
> > how to fix it.
> > >
> > > make ARCH=arm64 distclean
> > > make ARCH=arm64 allmodconfig
> > > make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1 / make -j8
> > ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=2 / make -j8
> > ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=3
> > >
> > > I saw many unrelated warnings...
> > 
> > Then it could be sparse. Install sparse and use C=1.
> 
> After applying the patch #2, I tried to use C=1 yesterday, I double check it today, still no warnings. Anything I missing?
> 
> $ make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1,C=1
>   CALL    scripts/atomic/check-atomics.sh
>   CALL    scripts/checksyscalls.sh
>   CHK     include/generated/compile.h
>   CHK     kernel/kheaders_data.tar.xz
>   CC [M]  drivers/net/ethernet/freescale/fec_main.o
>   LD [M]  drivers/net/ethernet/freescale/fec.o
>   MODPOST modules-only.symvers
>   GEN     Module.symvers
>   CC [M]  drivers/net/ethernet/freescale/fec.mod.o
>   LD [M]  drivers/net/ethernet/freescale/fec.ko
> 
> Best Regards,
> Joakim Zhang
> >      Andrew


If you look at
https://patchwork.hopto.org/static/nipa/498729/12315211/build_32bit/stdout

you see:

Kernel: arch/x86/boot/bzImage is ready  (#9396)

So it is building for 32 bit x86. So try

make -j8 ARCH=i386 W=1 C=1

Assuming your host is an x86 machine.

	 Andrew

RE: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations

[Joakim Zhang]

Hi Andrew,

> -----Original Message-----
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: 2021年6月17日 21:04
> To: Joakim Zhang <qiangqing.zhang@nxp.com>
> Cc: David Miller <davem@davemloft.net>; kuba@kernel.org;
> frieder.schrempf@kontron.de; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth fluctuations
> 
> On Thu, Jun 17, 2021 at 11:40:58AM +0000, Joakim Zhang wrote:
> >
> > Hi Andrew,
> >
> > > -----Original Message-----
> > > From: Andrew Lunn <andrew@lunn.ch>
> > > Sent: 2021年6月16日 21:06
> > > To: Joakim Zhang <qiangqing.zhang@nxp.com>
> > > Cc: David Miller <davem@davemloft.net>; kuba@kernel.org;
> > > frieder.schrempf@kontron.de; netdev@vger.kernel.org;
> > > linux-kernel@vger.kernel.org
> > > Subject: Re: [PATCH V2 net-next 0/2] net: fec: fix TX bandwidth
> > > fluctuations
> > >
> > > > I try below build options, also can't reproduce this issue, so
> > > > really don't know
> > > how to fix it.
> > > >
> > > > make ARCH=arm64 distclean
> > > > make ARCH=arm64 allmodconfig
> > > > make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1 / make
> > > > -j8
> > > ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=2 / make -j8
> > > ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=3
> > > >
> > > > I saw many unrelated warnings...
> > >
> > > Then it could be sparse. Install sparse and use C=1.
> >
> > After applying the patch #2, I tried to use C=1 yesterday, I double check it
> today, still no warnings. Anything I missing?
> >
> > $ make -j8 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- W=1,C=1
> >   CALL    scripts/atomic/check-atomics.sh
> >   CALL    scripts/checksyscalls.sh
> >   CHK     include/generated/compile.h
> >   CHK     kernel/kheaders_data.tar.xz
> >   CC [M]  drivers/net/ethernet/freescale/fec_main.o
> >   LD [M]  drivers/net/ethernet/freescale/fec.o
> >   MODPOST modules-only.symvers
> >   GEN     Module.symvers
> >   CC [M]  drivers/net/ethernet/freescale/fec.mod.o
> >   LD [M]  drivers/net/ethernet/freescale/fec.ko
> >
> > Best Regards,
> > Joakim Zhang
> > >      Andrew
> 
> 
> If you look at
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchw
> ork.hopto.org%2Fstatic%2Fnipa%2F498729%2F12315211%2Fbuild_32bit%2Fst
> dout&amp;data=04%7C01%7Cqiangqing.zhang%40nxp.com%7Ce966882aff15
> 41ed54c108d931906ad2%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0
> %7C637595318610458379%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjA
> wMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;s
> data=0o34i6pkvqBN1hPApz5Ja8CHjtqn8iwQB8whxg0p8Rw%3D&amp;reserved
> =0
> 
> you see:
> 
> Kernel: arch/x86/boot/bzImage is ready  (#9396)
> 
> So it is building for 32 bit x86. So try
> 
> make -j8 ARCH=i386 W=1 C=1
> 
> Assuming your host is an x86 machine.

Much thanks.

$ git am 0002-net-fec-add-ndo_select_queue-to-fix-TX-bandwidth-flu.patch
Applying: net: fec: add ndo_select_queue to fix TX bandwidth fluctuations
$ make -j8 ARCH=i386 W=1,C=1
  CALL    scripts/atomic/check-atomics.sh
  CALL    scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  CHK     kernel/kheaders_data.tar.xz
  CC [M]  drivers/net/ethernet/freescale/fec_main.o
  LD [M]  drivers/net/ethernet/freescale/fec.o
  MODPOST modules-only.symvers
Kernel: arch/x86/boot/bzImage is ready  (#1)
  GEN     Module.symvers
  CC [M]  drivers/net/ethernet/freescale/fec.mod.o
  LD [M]  drivers/net/ethernet/freescale/fec.ko

Unfortunately, I still can't see warnings after changing to build x86 image, a strange phenomenon, "W=1 C=1" seems not work, "W=1,C=1" can work.
I also save all of the build logs to double check, there is no build warnings related to FEC driver. 

Best Regards,
Joakim Zhang
> 	 Andrew

Re: [PATCH V2 2/2] net: fec: add ndo_select_queue to fix TX bandwidth fluctuations

[kernel test robot]

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Hi Joakim,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Joakim-Zhang/net-fec-fix-TX-bandwidth-fluctuations/20210616-221117
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git c7654495916e109f76a67fd3ae68f8fa70ab4faa
config: parisc-randconfig-s031-20210618 (attached as .config)
compiler: hppa-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-341-g8af24329-dirty
        # https://github.com/0day-ci/linux/commit/a0ef15273c2798319e07a8277161e99b4a22b41e
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Joakim-Zhang/net-fec-fix-TX-bandwidth-fluctuations/20210616-221117
        git checkout a0ef15273c2798319e07a8277161e99b4a22b41e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=parisc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
>> drivers/net/ethernet/freescale/fec_main.c:3250:30: sparse: sparse: cast to restricted __be16
>> drivers/net/ethernet/freescale/fec_main.c:3250:16: sparse: sparse: restricted __be16 degrades to integer

vim +3250 drivers/net/ethernet/freescale/fec_main.c

  3244	
  3245	static u16 fec_enet_get_raw_vlan_tci(struct sk_buff *skb)
  3246	{
  3247		struct vlan_ethhdr *vhdr;
  3248		unsigned short vlan_TCI = 0;
  3249	
> 3250		if (skb->protocol == ntohs(ETH_P_ALL)) {
  3251			vhdr = (struct vlan_ethhdr *)(skb->data);
  3252			vlan_TCI = ntohs(vhdr->h_vlan_TCI);
  3253		}
  3254	
  3255		return vlan_TCI;
  3256	}
  3257	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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