[net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Xiaolei Wang]

When the port is relinked, if the speed changes, the CBS parameters
should be updated, so saving the user transmission parameters so
that idle_slope and send_slope can be recalculated after the speed
changes after linking up can help reconfigure CBS after the speed
changes.

Fixes: 1f705bc61aee ("net: stmmac: Add support for CBS QDISC")
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
---
v1 -> v2
 - Update CBS parameters when speed changes

 drivers/net/ethernet/stmicro/stmmac/stmmac.h  |  4 ++
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 45 ++++++++++++++++++-
 .../net/ethernet/stmicro/stmmac/stmmac_tc.c   |  6 +++
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index b23b920eedb1..7a386b43f117 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -356,6 +356,10 @@ struct stmmac_priv {
 	unsigned int rfs_entries_total;
 	struct stmmac_rfs_entry *rfs_entries;
 
+	/* Save CBS configuration to adjust parameters when port link up speed changes */
+	s32 old_idleslope[MTL_MAX_TX_QUEUES];
+	s32 old_sendslope[MTL_MAX_TX_QUEUES];
+
 	/* Pulse Per Second output */
 	struct stmmac_pps_cfg pps[STMMAC_PPS_MAX];
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b3afc7cb7d72..44db35a7ca6a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -138,6 +138,7 @@ static void stmmac_tx_timer_arm(struct stmmac_priv *priv, u32 queue);
 static void stmmac_flush_tx_descriptors(struct stmmac_priv *priv, int queue);
 static void stmmac_set_dma_operation_mode(struct stmmac_priv *priv, u32 txmode,
 					  u32 rxmode, u32 chan);
+static void stmmac_configure_cbs(struct stmmac_priv *priv);
 
 #ifdef CONFIG_DEBUG_FS
 static const struct net_device_ops stmmac_netdev_ops;
@@ -1075,7 +1076,11 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 		}
 	}
 
-	priv->speed = speed;
+	/* Update speed and CBS parameters when speed changes */
+	if (speed != priv->speed) {
+		priv->speed = speed;
+		stmmac_configure_cbs(priv);
+	}
 
 	if (priv->plat->fix_mac_speed)
 		priv->plat->fix_mac_speed(priv->plat->bsp_priv, speed, mode);
@@ -1115,6 +1120,7 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 
 	if (priv->plat->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY)
 		stmmac_hwtstamp_correct_latency(priv, priv);
+
 }
 
 static const struct phylink_mac_ops stmmac_phylink_mac_ops = {
@@ -3182,13 +3188,42 @@ static void stmmac_set_tx_queue_weight(struct stmmac_priv *priv)
 /**
  *  stmmac_configure_cbs - Configure CBS in TX queue
  *  @priv: driver private structure
- *  Description: It is used for configuring CBS in AVB TX queues
+ *  Description: It is used for configuring CBS in AVB TX queues,
+ *  and when the speed changes, update CBS parameters to reconfigure
  */
 static void stmmac_configure_cbs(struct stmmac_priv *priv)
 {
 	u32 tx_queues_count = priv->plat->tx_queues_to_use;
 	u32 mode_to_use;
 	u32 queue;
+	u32 ptr, speed_div;
+	u64 value;
+
+	/* Port Transmit Rate and Speed Divider */
+	switch (priv->speed) {
+	case SPEED_10000:
+		ptr = 32;
+		speed_div = 10000000;
+		break;
+	case SPEED_5000:
+		ptr = 32;
+		speed_div = 5000000;
+		break;
+	case SPEED_2500:
+		ptr = 8;
+		speed_div = 2500000;
+		break;
+	case SPEED_1000:
+		ptr = 8;
+		speed_div = 1000000;
+		break;
+	case SPEED_100:
+		ptr = 4;
+		speed_div = 100000;
+		break;
+	default:
+		netdev_dbg(priv->dev, "link speed is not known\n");
+	}
 
 	/* queue 0 is reserved for legacy traffic */
 	for (queue = 1; queue < tx_queues_count; queue++) {
@@ -3196,6 +3231,12 @@ static void stmmac_configure_cbs(struct stmmac_priv *priv)
 		if (mode_to_use == MTL_QUEUE_DCB)
 			continue;
 
+		value = div_s64(priv->old_idleslope[queue] * 1024ll * ptr, speed_div);
+		priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0);
+
+		value = div_s64(-priv->old_sendslope[queue] * 1024ll * ptr, speed_div);
+		priv->plat->tx_queues_cfg[queue].send_slope = value & GENMASK(31, 0);
+
 		stmmac_config_cbs(priv, priv->hw,
 				priv->plat->tx_queues_cfg[queue].send_slope,
 				priv->plat->tx_queues_cfg[queue].idle_slope,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 222540b55480..d3526ad91aff 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -355,6 +355,9 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
 	if (!priv->dma_cap.av)
 		return -EOPNOTSUPP;
 
+	if (!netif_carrier_ok(priv->dev))
+		return -ENETDOWN;
+
 	/* Port Transmit Rate and Speed Divider */
 	switch (priv->speed) {
 	case SPEED_10000:
@@ -397,6 +400,9 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
 		priv->plat->tx_queues_cfg[queue].mode_to_use = MTL_QUEUE_DCB;
 	}
 
+	priv->old_idleslope[queue] = qopt->idleslope;
+	priv->old_sendslope[queue] = qopt->sendslope;
+
 	/* Final adjustments for HW */
 	value = div_s64(qopt->idleslope * 1024ll * ptr, speed_div);
 	priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0);
-- 
2.25.1

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Andrew Lunn]

>  static void stmmac_configure_cbs(struct stmmac_priv *priv)
>  {
>  	u32 tx_queues_count = priv->plat->tx_queues_to_use;
>  	u32 mode_to_use;
>  	u32 queue;
> +	u32 ptr, speed_div;
> +	u64 value;
> +
> +	/* Port Transmit Rate and Speed Divider */
> +	switch (priv->speed) {
> +	case SPEED_10000:
> +		ptr = 32;
> +		speed_div = 10000000;
> +		break;
> +	case SPEED_5000:
> +		ptr = 32;
> +		speed_div = 5000000;
> +		break;
> +	case SPEED_2500:
> +		ptr = 8;
> +		speed_div = 2500000;
> +		break;
> +	case SPEED_1000:
> +		ptr = 8;
> +		speed_div = 1000000;
> +		break;
> +	case SPEED_100:
> +		ptr = 4;
> +		speed_div = 100000;
> +		break;
> +	default:

No SPEED_10 ?

> +		netdev_dbg(priv->dev, "link speed is not known\n");
> +	}
>  
>  	/* queue 0 is reserved for legacy traffic */
>  	for (queue = 1; queue < tx_queues_count; queue++) {
> @@ -3196,6 +3231,12 @@ static void stmmac_configure_cbs(struct stmmac_priv *priv)
>  		if (mode_to_use == MTL_QUEUE_DCB)
>  			continue;
>  
> +		value = div_s64(priv->old_idleslope[queue] * 1024ll * ptr, speed_div);
> +		priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0);

Rather than masking off the top bits, shouldn't you be looking for
overflow? that indicates the configuration is not possible. You don't
have a good way to report the problem, since there is no user action
on link up, so you cannot return -EINVAL or -EOPNOTSUPP. So you
probably want to set the hardware as close as possible.

Also, what happens if the result of the div is 0? Does 0 have a
special meaning?

> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> index 222540b55480..d3526ad91aff 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> @@ -355,6 +355,9 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
>  	if (!priv->dma_cap.av)
>  		return -EOPNOTSUPP;
>  
> +	if (!netif_carrier_ok(priv->dev))
> +		return -ENETDOWN;
> +

Now that you are configuring the hardware on link up, does that
matter?

	Andrew

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Vladimir Oltean]

On Thu, May 30, 2024 at 02:50:52PM +0200, Xiaolei Wang wrote:
> When the port is relinked, if the speed changes, the CBS parameters
> should be updated, so saving the user transmission parameters so
> that idle_slope and send_slope can be recalculated after the speed
> changes after linking up can help reconfigure CBS after the speed
> changes.
> 
> Fixes: 1f705bc61aee ("net: stmmac: Add support for CBS QDISC")
> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
> ---
> v1 -> v2
>  - Update CBS parameters when speed changes

May I ask what is the point of this patch? The bandwidth fraction, as
IEEE 802.1Q defines it, it a function of idleSlope / portTransmitRate,
the latter of which is a runtime variant. If the link speed changes at
runtime, which is entirely possible, I see no alternative than to let
user space figure out that this happened, and decide what to do. This is
a consequence of the fact that the tc-cbs UAPI takes the raw idleSlope
as direct input, rather than something more high level like the desired
bandwidth for the stream itself, which could be dynamically computed by
the kernel.

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Russell King (Oracle)]

On Thu, May 30, 2024 at 04:28:22PM +0300, Vladimir Oltean wrote:
> On Thu, May 30, 2024 at 02:50:52PM +0200, Xiaolei Wang wrote:
> > When the port is relinked, if the speed changes, the CBS parameters
> > should be updated, so saving the user transmission parameters so
> > that idle_slope and send_slope can be recalculated after the speed
> > changes after linking up can help reconfigure CBS after the speed
> > changes.
> > 
> > Fixes: 1f705bc61aee ("net: stmmac: Add support for CBS QDISC")
> > Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
> > ---
> > v1 -> v2
> >  - Update CBS parameters when speed changes
> 
> May I ask what is the point of this patch? The bandwidth fraction, as
> IEEE 802.1Q defines it, it a function of idleSlope / portTransmitRate,
> the latter of which is a runtime variant. If the link speed changes at
> runtime, which is entirely possible, I see no alternative than to let
> user space figure out that this happened, and decide what to do. This is
> a consequence of the fact that the tc-cbs UAPI takes the raw idleSlope
> as direct input, rather than something more high level like the desired
> bandwidth for the stream itself, which could be dynamically computed by
> the kernel.

So what should be the behaviour here? Refuse setting CBS parameters if
the link is down, and clear the hardware configuration of the CBS
parameters each and every time there is a link-down event? Isn't that
going to make the driver's in-use settings inconsistent with what the
kernel thinks have been set? AFAIK, tc qdisc's don't vanish from the
kernel just because the link went down.

I think what you're proposing leads to the hardware being effectively
"de-programmed" for CBS while "tc qdisc show" will probably report
that CBS is active on the interface - which clearly would be absurd.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Vladimir Oltean]

On Thu, May 30, 2024 at 02:40:30PM +0100, Russell King (Oracle) wrote:
> On Thu, May 30, 2024 at 04:28:22PM +0300, Vladimir Oltean wrote:
> > On Thu, May 30, 2024 at 02:50:52PM +0200, Xiaolei Wang wrote:
> > > When the port is relinked, if the speed changes, the CBS parameters
> > > should be updated, so saving the user transmission parameters so
> > > that idle_slope and send_slope can be recalculated after the speed
> > > changes after linking up can help reconfigure CBS after the speed
> > > changes.
> > > 
> > > Fixes: 1f705bc61aee ("net: stmmac: Add support for CBS QDISC")
> > > Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
> > > ---
> > > v1 -> v2
> > >  - Update CBS parameters when speed changes
> > 
> > May I ask what is the point of this patch? The bandwidth fraction, as
> > IEEE 802.1Q defines it, it a function of idleSlope / portTransmitRate,
> > the latter of which is a runtime variant. If the link speed changes at
> > runtime, which is entirely possible, I see no alternative than to let
> > user space figure out that this happened, and decide what to do. This is
> > a consequence of the fact that the tc-cbs UAPI takes the raw idleSlope
> > as direct input, rather than something more high level like the desired
> > bandwidth for the stream itself, which could be dynamically computed by
> > the kernel.
> 
> So what should be the behaviour here? Refuse setting CBS parameters if
> the link is down, and clear the hardware configuration of the CBS
> parameters each and every time there is a link-down event? Isn't that
> going to make the driver's in-use settings inconsistent with what the
> kernel thinks have been set? AFAIK, tc qdisc's don't vanish from the
> kernel just because the link went down.
> 
> I think what you're proposing leads to the hardware being effectively
> "de-programmed" for CBS while "tc qdisc show" will probably report
> that CBS is active on the interface - which clearly would be absurd.

No, just program to hardware right away the idleSlope, sendSlope,
loCredit and hiCredit that were communicated by user space. Those were
computed for a specific link speed and it is user space's business to
monitor that this link speed is maintained for as long as the streams
are necessary (otherwise those parameters are no longer valid).
One could even recover the portTransmitRate that the parameters were
computed for (it should be idleSlope - sendSlope, in Kbps).

AKA keep the driver as it is.

I don't see why the CBS parameters would need to be de-programmed from
hardware on a link down event. Is that some stmmac specific thing?

Xiaolei may have a bone to pick with the fact that tc-cbs takes its
input the way it does, but that's an entirely different matter..

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Russell King (Oracle)]

On Thu, May 30, 2024 at 04:53:35PM +0300, Vladimir Oltean wrote:
> On Thu, May 30, 2024 at 02:40:30PM +0100, Russell King (Oracle) wrote:
> > On Thu, May 30, 2024 at 04:28:22PM +0300, Vladimir Oltean wrote:
> > > On Thu, May 30, 2024 at 02:50:52PM +0200, Xiaolei Wang wrote:
> > > > When the port is relinked, if the speed changes, the CBS parameters
> > > > should be updated, so saving the user transmission parameters so
> > > > that idle_slope and send_slope can be recalculated after the speed
> > > > changes after linking up can help reconfigure CBS after the speed
> > > > changes.
> > > > 
> > > > Fixes: 1f705bc61aee ("net: stmmac: Add support for CBS QDISC")
> > > > Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
> > > > ---
> > > > v1 -> v2
> > > >  - Update CBS parameters when speed changes
> > > 
> > > May I ask what is the point of this patch? The bandwidth fraction, as
> > > IEEE 802.1Q defines it, it a function of idleSlope / portTransmitRate,
> > > the latter of which is a runtime variant. If the link speed changes at
> > > runtime, which is entirely possible, I see no alternative than to let
> > > user space figure out that this happened, and decide what to do. This is
> > > a consequence of the fact that the tc-cbs UAPI takes the raw idleSlope
> > > as direct input, rather than something more high level like the desired
> > > bandwidth for the stream itself, which could be dynamically computed by
> > > the kernel.
> > 
> > So what should be the behaviour here? Refuse setting CBS parameters if
> > the link is down, and clear the hardware configuration of the CBS
> > parameters each and every time there is a link-down event? Isn't that
> > going to make the driver's in-use settings inconsistent with what the
> > kernel thinks have been set? AFAIK, tc qdisc's don't vanish from the
> > kernel just because the link went down.
> > 
> > I think what you're proposing leads to the hardware being effectively
> > "de-programmed" for CBS while "tc qdisc show" will probably report
> > that CBS is active on the interface - which clearly would be absurd.
> 
> No, just program to hardware right away the idleSlope, sendSlope,
> loCredit and hiCredit that were communicated by user space. Those were
> computed for a specific link speed and it is user space's business to
> monitor that this link speed is maintained for as long as the streams
> are necessary (otherwise those parameters are no longer valid).
> One could even recover the portTransmitRate that the parameters were
> computed for (it should be idleSlope - sendSlope, in Kbps).
> 
> AKA keep the driver as it is.
> 
> I don't see why the CBS parameters would need to be de-programmed from
> hardware on a link down event. Is that some stmmac specific thing?

If the driver is having to do computation on the parameters based on
the link speed, then when the link speed changes, the parameters
no longer match what the kernel _thinks_ those parameters were
programmed with.

What I'm trying to get over to you is that what you propose causes
an inconsistency between how the hardware is _programmed_ to behave
for CBS and what the kernel reports the CBS settings are if the
link speed changes.

For example, if the link was operating at 10G, and the idle slope
set by userspace is A, and the send slope was B, tc qdisc show
will report an idle slope of A and send slope of B.

If the link speed now changes to 5G, then, without updating the
settings in the hardware, the multiplier for the register values
will have reduced by a factor of two, meaning they're twice as
large as they should be for values of A and B.

However, tc qdisc show continues to report that values of A and B
are being used, but the hardware is actually using 2 * A and 2 * B.

It's all very well saying that userspace should basically reconstruct
the tc settings when the link changes, but not everyone is aware of
that. I'm saying it's a problem if one isn't aware of this issue with
this hardware, and one looks at tc qdisc show output, and assumes
that reflects what is actually being used when it isn't.

It's quality of implmentation - as far as I'm concerned, the kernel
should *not* mislead the user like this.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Vladimir Oltean]

On Thu, May 30, 2024 at 03:14:48PM +0100, Russell King (Oracle) wrote:
> > I don't see why the CBS parameters would need to be de-programmed from
> > hardware on a link down event. Is that some stmmac specific thing?
> 
> If the driver is having to do computation on the parameters based on
> the link speed, then when the link speed changes, the parameters
> no longer match what the kernel _thinks_ those parameters were
> programmed with.
> 
> What I'm trying to get over to you is that what you propose causes
> an inconsistency between how the hardware is _programmed_ to behave
> for CBS and what the kernel reports the CBS settings are if the
> link speed changes.
> 
> It's all very well saying that userspace should basically reconstruct
> the tc settings when the link changes, but not everyone is aware of
> that. I'm saying it's a problem if one isn't aware of this issue with
> this hardware, and one looks at tc qdisc show output, and assumes
> that reflects what is actually being used when it isn't.
> 
> It's quality of implmentation - as far as I'm concerned, the kernel
> should *not* mislead the user like this.

I was saying that the tc-cbs parameters input into the kernel should
already have the link speed baked into them:
portTransmitRate = idleSlope - sendSlope. In theory one could feed any
data into the kernel, but this is based on the IEEE 802.1Q formulas.

I had missed the fact that there is a calculation dependent on
priv->speed within tc_setup_cbs(), and I'm sorry for that. I thought
that the values were passed unaltered down to stmmac_config_cbs(). So
"make no change to the driver" is no longer my recommendation.

In that case, my recommendation is to do as sja1105_setup_tc_cbs() does:
replace priv->speed with the portTransmitRate recovered from the tc-cbs
parameters, and fully expect that when the link speed changes, user
space comes along and changes those parameters.

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[xiaolei wang]

On 5/30/24 22:35, Vladimir Oltean wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Thu, May 30, 2024 at 03:14:48PM +0100, Russell King (Oracle) wrote:
>>> I don't see why the CBS parameters would need to be de-programmed from
>>> hardware on a link down event. Is that some stmmac specific thing?
>> If the driver is having to do computation on the parameters based on
>> the link speed, then when the link speed changes, the parameters
>> no longer match what the kernel _thinks_ those parameters were
>> programmed with.
>>
>> What I'm trying to get over to you is that what you propose causes
>> an inconsistency between how the hardware is _programmed_ to behave
>> for CBS and what the kernel reports the CBS settings are if the
>> link speed changes.
>>
>> It's all very well saying that userspace should basically reconstruct
>> the tc settings when the link changes, but not everyone is aware of
>> that. I'm saying it's a problem if one isn't aware of this issue with
>> this hardware, and one looks at tc qdisc show output, and assumes
>> that reflects what is actually being used when it isn't.
>>
>> It's quality of implmentation - as far as I'm concerned, the kernel
>> should *not* mislead the user like this.
> I was saying that the tc-cbs parameters input into the kernel should
> already have the link speed baked into them:
> portTransmitRate = idleSlope - sendSlope. In theory one could feed any
> data into the kernel, but this is based on the IEEE 802.1Q formulas.
>
> I had missed the fact that there is a calculation dependent on
> priv->speed within tc_setup_cbs(), and I'm sorry for that. I thought
> that the values were passed unaltered down to stmmac_config_cbs(). So
> "make no change to the driver" is no longer my recommendation.
>
> In that case, my recommendation is to do as sja1105_setup_tc_cbs() does:
> replace priv->speed with the portTransmitRate recovered from the tc-cbs
> parameters, and fully expect that when the link speed changes, user
> space comes along and changes those parameters.

I will try it

thanks

xiaolei

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Jakub Kicinski]

On Thu, 30 May 2024 14:40:30 +0100 Russell King (Oracle) wrote:
> I think what you're proposing leads to the hardware being effectively
> "de-programmed" for CBS while "tc qdisc show" will probably report
> that CBS is active on the interface - which clearly would be absurd.

FWIW the "switch-offloaded" qdiscs do support reporting that they got
"de-programmed" given that more complex hierarchies can easily go out
of what HW is capable of.

They call the driver from the .dump callback, nominally to get
stats (e.g. red_dump() -> red_dump_offload_stats()) but it also
refreshes the offloaded state (see qdisc_offload_dump_helper()).

For "NIC-offloaded" qdiscs (i.e. all traffic passes thru the host,
rather than being forwarded) the stats callback makes less sense.
But all this is to say that there _is_ precedent for clearing
qdisc "offloaded" bits.

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[Dan Carpenter]

Hi Xiaolei,

kernel test robot noticed the following build warnings:

url:    https://github.com/intel-lab-lkp/linux/commits/Xiaolei-Wang/net-stmmac-Update-CBS-parameters-when-speed-changes-after-linking-up/20240530-141843
base:   net/main
patch link:    https://lore.kernel.org/r/20240530061453.561708-1-xiaolei.wang%40windriver.com
patch subject: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up
config: i386-randconfig-141-20240604 (https://download.01.org/0day-ci/archive/20240605/202406050318.jsyBFsxx-lkp@intel.com/config)
compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202406050318.jsyBFsxx-lkp@intel.com/

New smatch warnings:
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:3234 stmmac_configure_cbs() error: uninitialized symbol 'ptr'.
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:3234 stmmac_configure_cbs() error: uninitialized symbol 'speed_div'.

vim +/ptr +3234 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

19d9187317979c Joao Pinto   2017-03-10  3194  static void stmmac_configure_cbs(struct stmmac_priv *priv)
19d9187317979c Joao Pinto   2017-03-10  3195  {
19d9187317979c Joao Pinto   2017-03-10  3196  	u32 tx_queues_count = priv->plat->tx_queues_to_use;
19d9187317979c Joao Pinto   2017-03-10  3197  	u32 mode_to_use;
19d9187317979c Joao Pinto   2017-03-10  3198  	u32 queue;
882212f550d669 Xiaolei Wang 2024-05-30  3199  	u32 ptr, speed_div;
882212f550d669 Xiaolei Wang 2024-05-30  3200  	u64 value;
882212f550d669 Xiaolei Wang 2024-05-30  3201  
882212f550d669 Xiaolei Wang 2024-05-30  3202  	/* Port Transmit Rate and Speed Divider */
882212f550d669 Xiaolei Wang 2024-05-30  3203  	switch (priv->speed) {
882212f550d669 Xiaolei Wang 2024-05-30  3204  	case SPEED_10000:
882212f550d669 Xiaolei Wang 2024-05-30  3205  		ptr = 32;
882212f550d669 Xiaolei Wang 2024-05-30  3206  		speed_div = 10000000;
882212f550d669 Xiaolei Wang 2024-05-30  3207  		break;
882212f550d669 Xiaolei Wang 2024-05-30  3208  	case SPEED_5000:
882212f550d669 Xiaolei Wang 2024-05-30  3209  		ptr = 32;
882212f550d669 Xiaolei Wang 2024-05-30  3210  		speed_div = 5000000;
882212f550d669 Xiaolei Wang 2024-05-30  3211  		break;
882212f550d669 Xiaolei Wang 2024-05-30  3212  	case SPEED_2500:
882212f550d669 Xiaolei Wang 2024-05-30  3213  		ptr = 8;
882212f550d669 Xiaolei Wang 2024-05-30  3214  		speed_div = 2500000;
882212f550d669 Xiaolei Wang 2024-05-30  3215  		break;
882212f550d669 Xiaolei Wang 2024-05-30  3216  	case SPEED_1000:
882212f550d669 Xiaolei Wang 2024-05-30  3217  		ptr = 8;
882212f550d669 Xiaolei Wang 2024-05-30  3218  		speed_div = 1000000;
882212f550d669 Xiaolei Wang 2024-05-30  3219  		break;
882212f550d669 Xiaolei Wang 2024-05-30  3220  	case SPEED_100:
882212f550d669 Xiaolei Wang 2024-05-30  3221  		ptr = 4;
882212f550d669 Xiaolei Wang 2024-05-30  3222  		speed_div = 100000;
882212f550d669 Xiaolei Wang 2024-05-30  3223  		break;
882212f550d669 Xiaolei Wang 2024-05-30  3224  	default:
882212f550d669 Xiaolei Wang 2024-05-30  3225  		netdev_dbg(priv->dev, "link speed is not known\n");

return;?

882212f550d669 Xiaolei Wang 2024-05-30  3226  	}
19d9187317979c Joao Pinto   2017-03-10  3227  
44781fef137896 Joao Pinto   2017-03-31  3228  	/* queue 0 is reserved for legacy traffic */
44781fef137896 Joao Pinto   2017-03-31  3229  	for (queue = 1; queue < tx_queues_count; queue++) {
19d9187317979c Joao Pinto   2017-03-10  3230  		mode_to_use = priv->plat->tx_queues_cfg[queue].mode_to_use;
19d9187317979c Joao Pinto   2017-03-10  3231  		if (mode_to_use == MTL_QUEUE_DCB)
19d9187317979c Joao Pinto   2017-03-10  3232  			continue;
19d9187317979c Joao Pinto   2017-03-10  3233  
882212f550d669 Xiaolei Wang 2024-05-30 @3234  		value = div_s64(priv->old_idleslope[queue] * 1024ll * ptr, speed_div);
                                                                                                              ^^^  ^^^^^^^^^^
Uninitialized.

882212f550d669 Xiaolei Wang 2024-05-30  3235  		priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0);
882212f550d669 Xiaolei Wang 2024-05-30  3236  
882212f550d669 Xiaolei Wang 2024-05-30  3237  		value = div_s64(-priv->old_sendslope[queue] * 1024ll * ptr, speed_div);
882212f550d669 Xiaolei Wang 2024-05-30  3238  		priv->plat->tx_queues_cfg[queue].send_slope = value & GENMASK(31, 0);
882212f550d669 Xiaolei Wang 2024-05-30  3239  
c10d4c82a5c84c Jose Abreu   2018-04-16  3240  		stmmac_config_cbs(priv, priv->hw,
19d9187317979c Joao Pinto   2017-03-10  3241  				priv->plat->tx_queues_cfg[queue].send_slope,
19d9187317979c Joao Pinto   2017-03-10  3242  				priv->plat->tx_queues_cfg[queue].idle_slope,
19d9187317979c Joao Pinto   2017-03-10  3243  				priv->plat->tx_queues_cfg[queue].high_credit,
19d9187317979c Joao Pinto   2017-03-10  3244  				priv->plat->tx_queues_cfg[queue].low_credit,
19d9187317979c Joao Pinto   2017-03-10  3245  				queue);
19d9187317979c Joao Pinto   2017-03-10  3246  	}
19d9187317979c Joao Pinto   2017-03-10  3247  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up

[xiaolei wang]

On 6/5/24 13:26, Dan Carpenter wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> Hi Xiaolei,
>
> kernel test robot noticed the following build warnings:

Please drop this patch as there are still some questions on this issue

thanks

xiaolei

>
> url:    https://github.com/intel-lab-lkp/linux/commits/Xiaolei-Wang/net-stmmac-Update-CBS-parameters-when-speed-changes-after-linking-up/20240530-141843
> base:   net/main
> patch link:    https://lore.kernel.org/r/20240530061453.561708-1-xiaolei.wang%40windriver.com
> patch subject: [net v2 PATCH] net: stmmac: Update CBS parameters when speed changes after linking up
> config: i386-randconfig-141-20240604 (https://download.01.org/0day-ci/archive/20240605/202406050318.jsyBFsxx-lkp@intel.com/config)
> compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> | Closes: https://lore.kernel.org/r/202406050318.jsyBFsxx-lkp@intel.com/
>
> New smatch warnings:
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:3234 stmmac_configure_cbs() error: uninitialized symbol 'ptr'.
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:3234 stmmac_configure_cbs() error: uninitialized symbol 'speed_div'.
>
> vim +/ptr +3234 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>
> 19d9187317979c Joao Pinto   2017-03-10  3194  static void stmmac_configure_cbs(struct stmmac_priv *priv)
> 19d9187317979c Joao Pinto   2017-03-10  3195  {
> 19d9187317979c Joao Pinto   2017-03-10  3196    u32 tx_queues_count = priv->plat->tx_queues_to_use;
> 19d9187317979c Joao Pinto   2017-03-10  3197    u32 mode_to_use;
> 19d9187317979c Joao Pinto   2017-03-10  3198    u32 queue;
> 882212f550d669 Xiaolei Wang 2024-05-30  3199    u32 ptr, speed_div;
> 882212f550d669 Xiaolei Wang 2024-05-30  3200    u64 value;
> 882212f550d669 Xiaolei Wang 2024-05-30  3201
> 882212f550d669 Xiaolei Wang 2024-05-30  3202    /* Port Transmit Rate and Speed Divider */
> 882212f550d669 Xiaolei Wang 2024-05-30  3203    switch (priv->speed) {
> 882212f550d669 Xiaolei Wang 2024-05-30  3204    case SPEED_10000:
> 882212f550d669 Xiaolei Wang 2024-05-30  3205            ptr = 32;
> 882212f550d669 Xiaolei Wang 2024-05-30  3206            speed_div = 10000000;
> 882212f550d669 Xiaolei Wang 2024-05-30  3207            break;
> 882212f550d669 Xiaolei Wang 2024-05-30  3208    case SPEED_5000:
> 882212f550d669 Xiaolei Wang 2024-05-30  3209            ptr = 32;
> 882212f550d669 Xiaolei Wang 2024-05-30  3210            speed_div = 5000000;
> 882212f550d669 Xiaolei Wang 2024-05-30  3211            break;
> 882212f550d669 Xiaolei Wang 2024-05-30  3212    case SPEED_2500:
> 882212f550d669 Xiaolei Wang 2024-05-30  3213            ptr = 8;
> 882212f550d669 Xiaolei Wang 2024-05-30  3214            speed_div = 2500000;
> 882212f550d669 Xiaolei Wang 2024-05-30  3215            break;
> 882212f550d669 Xiaolei Wang 2024-05-30  3216    case SPEED_1000:
> 882212f550d669 Xiaolei Wang 2024-05-30  3217            ptr = 8;
> 882212f550d669 Xiaolei Wang 2024-05-30  3218            speed_div = 1000000;
> 882212f550d669 Xiaolei Wang 2024-05-30  3219            break;
> 882212f550d669 Xiaolei Wang 2024-05-30  3220    case SPEED_100:
> 882212f550d669 Xiaolei Wang 2024-05-30  3221            ptr = 4;
> 882212f550d669 Xiaolei Wang 2024-05-30  3222            speed_div = 100000;
> 882212f550d669 Xiaolei Wang 2024-05-30  3223            break;
> 882212f550d669 Xiaolei Wang 2024-05-30  3224    default:
> 882212f550d669 Xiaolei Wang 2024-05-30  3225            netdev_dbg(priv->dev, "link speed is not known\n");
>
> return;?
>
> 882212f550d669 Xiaolei Wang 2024-05-30  3226    }
> 19d9187317979c Joao Pinto   2017-03-10  3227
> 44781fef137896 Joao Pinto   2017-03-31  3228    /* queue 0 is reserved for legacy traffic */
> 44781fef137896 Joao Pinto   2017-03-31  3229    for (queue = 1; queue < tx_queues_count; queue++) {
> 19d9187317979c Joao Pinto   2017-03-10  3230            mode_to_use = priv->plat->tx_queues_cfg[queue].mode_to_use;
> 19d9187317979c Joao Pinto   2017-03-10  3231            if (mode_to_use == MTL_QUEUE_DCB)
> 19d9187317979c Joao Pinto   2017-03-10  3232                    continue;
> 19d9187317979c Joao Pinto   2017-03-10  3233
> 882212f550d669 Xiaolei Wang 2024-05-30 @3234            value = div_s64(priv->old_idleslope[queue] * 1024ll * ptr, speed_div);
>                                                                                                                ^^^  ^^^^^^^^^^
> Uninitialized.
>
> 882212f550d669 Xiaolei Wang 2024-05-30  3235            priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0);
> 882212f550d669 Xiaolei Wang 2024-05-30  3236
> 882212f550d669 Xiaolei Wang 2024-05-30  3237            value = div_s64(-priv->old_sendslope[queue] * 1024ll * ptr, speed_div);
> 882212f550d669 Xiaolei Wang 2024-05-30  3238            priv->plat->tx_queues_cfg[queue].send_slope = value & GENMASK(31, 0);
> 882212f550d669 Xiaolei Wang 2024-05-30  3239
> c10d4c82a5c84c Jose Abreu   2018-04-16  3240            stmmac_config_cbs(priv, priv->hw,
> 19d9187317979c Joao Pinto   2017-03-10  3241                            priv->plat->tx_queues_cfg[queue].send_slope,
> 19d9187317979c Joao Pinto   2017-03-10  3242                            priv->plat->tx_queues_cfg[queue].idle_slope,
> 19d9187317979c Joao Pinto   2017-03-10  3243                            priv->plat->tx_queues_cfg[queue].high_credit,
> 19d9187317979c Joao Pinto   2017-03-10  3244                            priv->plat->tx_queues_cfg[queue].low_credit,
> 19d9187317979c Joao Pinto   2017-03-10  3245                            queue);
> 19d9187317979c Joao Pinto   2017-03-10  3246    }
> 19d9187317979c Joao Pinto   2017-03-10  3247  }
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
>