2023-06-14 14:26:35

by Florian Kauer

[permalink] [raw]
Subject: [PATCH net-next 0/6] igc: Fix corner cases for TSN offload

The igc driver supports several different offloading capabilities
relevant in the TSN context. Recent patches in this area introduced
regressions for certain corner cases that are fixed in this series.

Each of the patches (except the first one) addresses a different
regression that can be separately reproduced. Still, they have
overlapping code changes so they should not be separately applied.

Especially #4 and #6 address the same observation,
but both need to be applied to avoid TX hang occurrences in
the scenario described in the patches.

Signed-off-by: Florian Kauer <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>

Florian Kauer (6):
igc: Rename qbv_enable to taprio_offload_enable
igc: Do not enable taprio offload for invalid arguments
igc: Handle already enabled taprio offload for basetime 0
igc: No strict mode in pure launchtime/CBS offload
igc: Fix launchtime before start of cycle
igc: Fix inserting of empty frame for launchtime

drivers/net/ethernet/intel/igc/igc.h | 2 +-
drivers/net/ethernet/intel/igc/igc_main.c | 24 ++++++++-------------
drivers/net/ethernet/intel/igc/igc_tsn.c | 26 ++++++++++++++++++++---
3 files changed, 33 insertions(+), 19 deletions(-)

--
2.39.2



2023-06-14 14:31:09

by Florian Kauer

[permalink] [raw]
Subject: [PATCH net-next 6/6] igc: Fix inserting of empty frame for launchtime

The insertion of an empty frame was introduced with
commit db0b124f02ba ("igc: Enhance Qbv scheduling by using first flag bit")
in order to ensure that the current cycle has at least one packet if
there is some packet to be scheduled for the next cycle.

However, the current implementation does not properly check if
a packet is already scheduled for the current cycle. Currently,
an empty packet is always inserted if and only if
txtime >= end_of_cycle && txtime > last_tx_cycle
but since last_tx_cycle is always either the end of the current
cycle (end_of_cycle) or the end of a previous cycle, the
second part (txtime > last_tx_cycle) is always true unless
txtime == last_tx_cycle.

What actually needs to be checked here is if the last_tx_cycle
was already written within the current cycle, so an empty frame
should only be inserted if and only if
txtime >= end_of_cycle && end_of_cycle > last_tx_cycle.

This patch does not only avoid an unnecessary insertion, but it
can actually be harmful to insert an empty packet if packets
are already scheduled in the current cycle, because it can lead
to a situation where the empty packet is actually processed
as the first packet in the upcoming cycle shifting the packet
with the first_flag even one cycle into the future, finally leading
to a TX hang.

The TX hang can be reproduced on a i225 with:

sudo tc qdisc replace dev enp1s0 parent root handle 100 taprio \
num_tc 1 \
map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
queues 1@0 \
base-time 0 \
sched-entry S 01 300000 \
flags 0x1 \
txtime-delay 500000 \
clockid CLOCK_TAI
sudo tc qdisc replace dev enp1s0 parent 100:1 etf \
clockid CLOCK_TAI \
delta 500000 \
offload \
skip_sock_check

and traffic generator

sudo trafgen -i traffic.cfg -o enp1s0 --cpp -n0 -q -t1400ns

with traffic.cfg

#define ETH_P_IP 0x0800

{
/* Ethernet Header */
0x30, 0x1f, 0x9a, 0xd0, 0xf0, 0x0e, # MAC Dest - adapt as needed
0x24, 0x5e, 0xbe, 0x57, 0x2e, 0x36, # MAC Src - adapt as needed
const16(ETH_P_IP),

/* IPv4 Header */
0b01000101, 0, # IPv4 version, IHL, TOS
const16(1028), # IPv4 total length (UDP length + 20 bytes (IP header))
const16(2), # IPv4 ident
0b01000000, 0, # IPv4 flags, fragmentation off
64, # IPv4 TTL
17, # Protocol UDP
csumip(14, 33), # IPv4 checksum

/* UDP Header */
10, 0, 48, 1, # IP Src - adapt as needed
10, 0, 48, 10, # IP Dest - adapt as needed
const16(5555), # UDP Src Port
const16(6666), # UDP Dest Port
const16(1008), # UDP length (UDP header 8 bytes + payload length)
csumudp(14, 34), # UDP checksum

/* Payload */
fill('W', 1000),
}

and the observed message with that is for example

igc 0000:01:00.0 enp1s0: Detected Tx Unit Hang
Tx Queue <0>
TDH <32>
TDT <3c>
next_to_use <3c>
next_to_clean <32>
buffer_info[next_to_clean]
time_stamp <ffff26a8>
next_to_watch <00000000632a1828>
jiffies <ffff27f8>
desc.status <1048000>

Fixes: db0b124f02ba ("igc: Enhance Qbv scheduling by using first flag bit")
Signed-off-by: Florian Kauer <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>
---
drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index ec8649751d19..1556beaefbc3 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1023,7 +1023,7 @@ static __le32 igc_tx_launchtime(struct igc_ring *ring, ktime_t txtime,
*first_flag = true;
ring->last_ff_cycle = baset_est;

- if (ktime_compare(txtime, ring->last_tx_cycle) > 0)
+ if (ktime_compare(end_of_cycle, ring->last_tx_cycle) > 0)
*insert_empty = true;
}
}
--
2.39.2


2023-06-14 14:35:16

by Florian Kauer

[permalink] [raw]
Subject: [PATCH net-next 3/6] igc: Handle already enabled taprio offload for basetime 0

Since commit e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")
it is possible to enable taprio offload with a basetime of 0.
However, the check if taprio offload is already enabled (and thus -EALREADY
should be returned for igc_save_qbv_schedule) still relied on
adapter->base_time > 0.

This can be reproduced as follows:

# TAPRIO offload (flags == 0x2) and base-time = 0
sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24 taprio \
num_tc 1 \
map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
queues 1@0 \
base-time 0 \
sched-entry S 01 300000 \
flags 0x2

# The second call should fail with "Error: Device failed to setup taprio offload."
# But that only happens if base-time was != 0
sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24 taprio \
num_tc 1 \
map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
queues 1@0 \
base-time 0 \
sched-entry S 01 300000 \
flags 0x2

Fixes: e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")
Signed-off-by: Florian Kauer <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>
---
drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 122158b321d5..35ace8d338a5 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6123,7 +6123,7 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
if (qopt->base_time < 0)
return -ERANGE;

- if (igc_is_device_id_i225(hw) && adapter->base_time)
+ if (igc_is_device_id_i225(hw) && adapter->taprio_offload_enable)
return -EALREADY;

if (!validate_schedule(adapter, qopt))
--
2.39.2


2023-06-14 14:36:36

by Florian Kauer

[permalink] [raw]
Subject: [PATCH net-next 2/6] igc: Do not enable taprio offload for invalid arguments

Only set adapter->taprio_offload_enable after validating the arguments.
Otherwise, it stays set even if the offload was not enabled.
Since the subsequent code does not get executed in case of invalid
arguments, it will not be read at first.
However, by activating and then deactivating another offload
(e.g. ETF/TX launchtime offload), taprio_offload_enable is read
and erroneously keeps the offload feature of the NIC enabled.

This can be reproduced as follows:

# TAPRIO offload (flags == 0x2) and negative base-time leading to expected -ERANGE
sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24 taprio \
num_tc 1 \
map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
queues 1@0 \
base-time -1000 \
sched-entry S 01 300000 \
flags 0x2

# IGC_TQAVCTRL is 0x0 as expected (iomem=relaxed for reading register)
sudo pcimem /sys/bus/pci/devices/0000:01:00.0/resource0 0x3570 w*1

# Activate ETF offload
sudo tc qdisc replace dev enp1s0 parent root handle 6666 mqprio \
num_tc 3 \
map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
queues 1@0 1@1 2@2 \
hw 0
sudo tc qdisc add dev enp1s0 parent 6666:1 etf \
clockid CLOCK_TAI \
delta 500000 \
offload

# IGC_TQAVCTRL is 0x9 as expected
sudo pcimem /sys/bus/pci/devices/0000:01:00.0/resource0 0x3570 w*1

# Deactivate ETF offload again
sudo tc qdisc delete dev enp1s0 parent 6666:1

# IGC_TQAVCTRL should now be 0x0 again, but is observed as 0x9
sudo pcimem /sys/bus/pci/devices/0000:01:00.0/resource0 0x3570 w*1

Fixes: e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")
Signed-off-by: Florian Kauer <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>
---
drivers/net/ethernet/intel/igc/igc_main.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 56117846b8da..122158b321d5 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6091,6 +6091,7 @@ static int igc_tsn_clear_schedule(struct igc_adapter *adapter)

adapter->base_time = 0;
adapter->cycle_time = NSEC_PER_SEC;
+ adapter->taprio_offload_enable = false;
adapter->qbv_config_change_errors = 0;

for (i = 0; i < adapter->num_tx_queues; i++) {
@@ -6113,20 +6114,12 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
size_t n;
int i;

- switch (qopt->cmd) {
- case TAPRIO_CMD_REPLACE:
- adapter->taprio_offload_enable = true;
- break;
- case TAPRIO_CMD_DESTROY:
- adapter->taprio_offload_enable = false;
- break;
- default:
- return -EOPNOTSUPP;
- }
-
- if (!adapter->taprio_offload_enable)
+ if (qopt->cmd == TAPRIO_CMD_DESTROY)
return igc_tsn_clear_schedule(adapter);

+ if (qopt->cmd != TAPRIO_CMD_REPLACE)
+ return -EOPNOTSUPP;
+
if (qopt->base_time < 0)
return -ERANGE;

@@ -6138,6 +6131,7 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,

adapter->cycle_time = qopt->cycle_time;
adapter->base_time = qopt->base_time;
+ adapter->taprio_offload_enable = true;

for (n = 0; n < qopt->num_entries; n++) {
struct tc_taprio_sched_entry *e = &qopt->entries[n];
--
2.39.2


2023-06-14 14:42:00

by Florian Kauer

[permalink] [raw]
Subject: [PATCH net-next 4/6] igc: No strict mode in pure launchtime/CBS offload

The flags IGC_TXQCTL_STRICT_CYCLE and IGC_TXQCTL_STRICT_END
prevent the packet transmission over slot and cycle boundaries.
This is important for taprio offload where the slots and
cycles correspond to the slots and cycles configured for the
network.

However, the Qbv offload feature of the i225 is also used for
enabling TX launchtime / ETF offload. In that case, however,
the cycle has no meaning for the network and is only used
internally to adapt the base time register after a second has
passed.

Enabling strict mode in this case would unneccesarily prevent
the transmission of certain packets (i.e. at the boundary of a
second) and thus interfers with the ETF qdisc that promises
transmission at a certain point in time.

Similar to ETF, this also applies to CBS offload that also should
not be influenced by strict mode unless taprio offload would be
enabled at the same time.

This fully reverts
commit d8f45be01dd9 ("igc: Use strict cycles for Qbv scheduling")
but its commit message only describes what was already implemented
before that commit. The difference to a plain revert of that commit
is that it now copes with the base_time = 0 case that was fixed with
commit e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")

In particular, enabling strict mode leads to TX hang situations
under high traffic if taprio is applied WITHOUT taprio offload
but WITH ETF offload, e.g. as in

sudo tc qdisc replace dev enp1s0 parent root handle 100 taprio \
num_tc 1 \
map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
queues 1@0 \
base-time 0 \
sched-entry S 01 300000 \
flags 0x1 \
txtime-delay 500000 \
clockid CLOCK_TAI
sudo tc qdisc replace dev enp1s0 parent 100:1 etf \
clockid CLOCK_TAI \
delta 500000 \
offload \
skip_sock_check

and traffic generator

sudo trafgen -i traffic.cfg -o enp1s0 --cpp -n0 -q -t1400ns

with traffic.cfg

#define ETH_P_IP 0x0800

{
/* Ethernet Header */
0x30, 0x1f, 0x9a, 0xd0, 0xf0, 0x0e, # MAC Dest - adapt as needed
0x24, 0x5e, 0xbe, 0x57, 0x2e, 0x36, # MAC Src - adapt as needed
const16(ETH_P_IP),

/* IPv4 Header */
0b01000101, 0, # IPv4 version, IHL, TOS
const16(1028), # IPv4 total length (UDP length + 20 bytes (IP header))
const16(2), # IPv4 ident
0b01000000, 0, # IPv4 flags, fragmentation off
64, # IPv4 TTL
17, # Protocol UDP
csumip(14, 33), # IPv4 checksum

/* UDP Header */
10, 0, 48, 1, # IP Src - adapt as needed
10, 0, 48, 10, # IP Dest - adapt as needed
const16(5555), # UDP Src Port
const16(6666), # UDP Dest Port
const16(1008), # UDP length (UDP header 8 bytes + payload length)
csumudp(14, 34), # UDP checksum

/* Payload */
fill('W', 1000),
}

and the observed message with that is for example

igc 0000:01:00.0 enp1s0: Detected Tx Unit Hang
Tx Queue <0>
TDH <d0>
TDT <f0>
next_to_use <f0>
next_to_clean <d0>
buffer_info[next_to_clean]
time_stamp <ffff661f>
next_to_watch <00000000245a4efb>
jiffies <ffff6e48>
desc.status <1048000>

Fixes: d8f45be01dd9 ("igc: Use strict cycles for Qbv scheduling")
Signed-off-by: Florian Kauer <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>
---
drivers/net/ethernet/intel/igc/igc_tsn.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index c6636a7264d5..63d410e7b876 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -133,8 +133,28 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
wr32(IGC_STQT(i), ring->start_time);
wr32(IGC_ENDQT(i), ring->end_time);

- txqctl |= IGC_TXQCTL_STRICT_CYCLE |
- IGC_TXQCTL_STRICT_END;
+ if (adapter->taprio_offload_enable) {
+ /* If taprio_offload_enable is set we are in "taprio"
+ * mode and we need to be strict about the
+ * cycles: only transmit a packet if it can be
+ * completed during that cycle.
+ *
+ * If taprio_offload_enable is NOT true when
+ * enabling TSN offload, the cycle should have
+ * no external effects, but is only used internally
+ * to adapt the base time register after a second
+ * has passed.
+ *
+ * Enabling strict mode in this case would
+ * unneccesarily prevent the transmission of
+ * certain packets (i.e. at the boundary of a
+ * second) and thus interfer with the launchtime
+ * feature that promises transmission at a
+ * certain point in time.
+ */
+ txqctl |= IGC_TXQCTL_STRICT_CYCLE |
+ IGC_TXQCTL_STRICT_END;
+ }

if (ring->launchtime_enable)
txqctl |= IGC_TXQCTL_QUEUE_MODE_LAUNCHT;
--
2.39.2


2023-06-14 14:43:32

by Florian Kauer

[permalink] [raw]
Subject: [PATCH net-next 5/6] igc: Fix launchtime before start of cycle

It is possible (verified on a running system) that frames are processed
by igc_tx_launchtime with a txtime before the start of the cycle
(baset_est).

However, the result of txtime - baset_est is written into a u32,
leading to a wrap around to a positive number. The following
launchtime > 0 check will only branch to executing launchtime = 0
if launchtime is already 0.

Fix it by using a s32 before checking launchtime > 0.

Fixes: db0b124f02ba ("igc: Enhance Qbv scheduling by using first flag bit")
Signed-off-by: Florian Kauer <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>
---
drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 35ace8d338a5..ec8649751d19 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1010,7 +1010,7 @@ static __le32 igc_tx_launchtime(struct igc_ring *ring, ktime_t txtime,
ktime_t base_time = adapter->base_time;
ktime_t now = ktime_get_clocktai();
ktime_t baset_est, end_of_cycle;
- u32 launchtime;
+ s32 launchtime;
s64 n;

n = div64_s64(ktime_sub_ns(now, base_time), cycle_time);
--
2.39.2


2023-06-14 14:45:44

by Florian Kauer

[permalink] [raw]
Subject: [PATCH net-next 1/6] igc: Rename qbv_enable to taprio_offload_enable

In the current implementation the flags adapter->qbv_enable
and IGC_FLAG_TSN_QBV_ENABLED have a similar name, but do not
have the same meaning. The first one is used only to indicate
taprio offload (i.e. when igc_save_qbv_schedule was called),
while the second one corresponds to the Qbv mode of the hardware.
However, the second one is also used to support the TX launchtime
feature, i.e. ETF qdisc offload. This leads to situations where
adapter->qbv_enable is false, but the flag IGC_FLAG_TSN_QBV_ENABLED
is set. This is prone to confusion.

The rename should reduce this confusion. Since it is a pure
rename, it has no impact on functionality.

Fixes: e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")
Signed-off-by: Florian Kauer <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>
---
drivers/net/ethernet/intel/igc/igc.h | 2 +-
drivers/net/ethernet/intel/igc/igc_main.c | 6 +++---
drivers/net/ethernet/intel/igc/igc_tsn.c | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 18d4af934d8c..4d22662e8021 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -186,7 +186,7 @@ struct igc_adapter {

ktime_t base_time;
ktime_t cycle_time;
- bool qbv_enable;
+ bool taprio_offload_enable;
u32 qbv_config_change_errors;

/* OS defined structs */
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 88145c30c919..56117846b8da 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6115,16 +6115,16 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,

switch (qopt->cmd) {
case TAPRIO_CMD_REPLACE:
- adapter->qbv_enable = true;
+ adapter->taprio_offload_enable = true;
break;
case TAPRIO_CMD_DESTROY:
- adapter->qbv_enable = false;
+ adapter->taprio_offload_enable = false;
break;
default:
return -EOPNOTSUPP;
}

- if (!adapter->qbv_enable)
+ if (!adapter->taprio_offload_enable)
return igc_tsn_clear_schedule(adapter);

if (qopt->base_time < 0)
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 94a2b0dfb54d..c6636a7264d5 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -37,7 +37,7 @@ static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
{
unsigned int new_flags = adapter->flags & ~IGC_FLAG_TSN_ANY_ENABLED;

- if (adapter->qbv_enable)
+ if (adapter->taprio_offload_enable)
new_flags |= IGC_FLAG_TSN_QBV_ENABLED;

if (is_any_launchtime(adapter))
--
2.39.2


Subject: RE: [PATCH net-next 0/6] igc: Fix corner cases for TSN offload

Dear Florian,

Thanks for the patch series ????

> -----Original Message-----
> From: Florian Kauer <[email protected]>
> Sent: Wednesday, 14 June, 2023 10:07 PM
> To: Brandeburg, Jesse <[email protected]>; Nguyen, Anthony L
> <[email protected]>; Gomes, Vinicius <[email protected]>;
> David S . Miller <[email protected]>; Eric Dumazet
> <[email protected]>; Jakub Kicinski <[email protected]>; Paolo Abeni
> <[email protected]>; Tan Tee Min <[email protected]>; Zulkifli,
> Muhammad Husaini <[email protected]>; Gunasekaran,
> Aravindhan <[email protected]>; Chilakala, Mallikarjuna
> <[email protected]>
> Cc: [email protected]; [email protected]; linux-
> [email protected]; [email protected]; [email protected]
> Subject: [PATCH net-next 0/6] igc: Fix corner cases for TSN offload
>
> The igc driver supports several different offloading capabilities relevant in the
> TSN context. Recent patches in this area introduced regressions for certain
> corner cases that are fixed in this series.
>
> Each of the patches (except the first one) addresses a different regression that
> can be separately reproduced. Still, they have overlapping code changes so they
> should not be separately applied.
>
> Especially #4 and #6 address the same observation, but both need to be applied
> to avoid TX hang occurrences in the scenario described in the patches.
>
> Signed-off-by: Florian Kauer <[email protected]>
> Reviewed-by: Kurt Kanzenbach <[email protected]>
>
> Florian Kauer (6):
> igc: Rename qbv_enable to taprio_offload_enable
> igc: Do not enable taprio offload for invalid arguments
> igc: Handle already enabled taprio offload for basetime 0
> igc: No strict mode in pure launchtime/CBS offload
> igc: Fix launchtime before start of cycle
> igc: Fix inserting of empty frame for launchtime

All six patches, as far as I can see here, have the Fixes tag. Should they go to Net instead of Net-Next?

>
> drivers/net/ethernet/intel/igc/igc.h | 2 +-
> drivers/net/ethernet/intel/igc/igc_main.c | 24 ++++++++-------------
> drivers/net/ethernet/intel/igc/igc_tsn.c | 26 ++++++++++++++++++++---
> 3 files changed, 33 insertions(+), 19 deletions(-)
>
> --
> 2.39.2

2023-06-16 16:31:21

by Florian Kauer

[permalink] [raw]
Subject: Re: [PATCH net-next 0/6] igc: Fix corner cases for TSN offload

On 16.06.23 17:53, Zulkifli, Muhammad Husaini wrote:
>> Florian Kauer (6):
>> igc: Rename qbv_enable to taprio_offload_enable
>> igc: Do not enable taprio offload for invalid arguments
>> igc: Handle already enabled taprio offload for basetime 0
>> igc: No strict mode in pure launchtime/CBS offload
>> igc: Fix launchtime before start of cycle
>> igc: Fix inserting of empty frame for launchtime
>
> All six patches, as far as I can see here, have the Fixes tag. Should they go to Net instead of Net-Next?

You are correct, these are all fixes and could go to net.
However, in its current form they will not fully apply to net
(e.g. due to the commit 2d800bc500fb ("net/sched: taprio: replace tc_taprio_qopt_offload :: enable with a "cmd" enum")
that has overlapping code changes) and are also not tested with net.
If you prefer to have them in net already I could send a second series.
For me personally all options (net, net-next or iwl-next) would be fine.

Thanks,
Florian

Subject: RE: [PATCH net-next 3/6] igc: Handle already enabled taprio offload for basetime 0

Dear Florian,

> -----Original Message-----
> From: Florian Kauer <[email protected]>
> Sent: Wednesday, 14 June, 2023 10:07 PM
> To: Brandeburg, Jesse <[email protected]>; Nguyen, Anthony L
> <[email protected]>; Gomes, Vinicius <[email protected]>;
> David S . Miller <[email protected]>; Eric Dumazet
> <[email protected]>; Jakub Kicinski <[email protected]>; Paolo Abeni
> <[email protected]>; Tan Tee Min <[email protected]>; Zulkifli,
> Muhammad Husaini <[email protected]>; Gunasekaran,
> Aravindhan <[email protected]>; Chilakala, Mallikarjuna
> <[email protected]>
> Cc: [email protected]; [email protected]; linux-
> [email protected]; [email protected]; [email protected]
> Subject: [PATCH net-next 3/6] igc: Handle already enabled taprio offload for
> basetime 0
>
> Since commit e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv") it is
> possible to enable taprio offload with a basetime of 0.
> However, the check if taprio offload is already enabled (and thus -EALREADY
> should be returned for igc_save_qbv_schedule) still relied on
> adapter->base_time > 0.
>
> This can be reproduced as follows:
>
> # TAPRIO offload (flags == 0x2) and base-time = 0
> sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24
> taprio \
> num_tc 1 \
> map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
> queues 1@0 \
> base-time 0 \
> sched-entry S 01 300000 \
> flags 0x2
>
> # The second call should fail with "Error: Device failed to setup taprio offload."
> # But that only happens if base-time was != 0
> sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24
> taprio \
> num_tc 1 \
> map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
> queues 1@0 \
> base-time 0 \
> sched-entry S 01 300000 \
> flags 0x2
>
> Fixes: e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")
> Signed-off-by: Florian Kauer <[email protected]>
> Reviewed-by: Kurt Kanzenbach <[email protected]>
> ---
> drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
> b/drivers/net/ethernet/intel/igc/igc_main.c
> index 122158b321d5..35ace8d338a5 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -6123,7 +6123,7 @@ static int igc_save_qbv_schedule(struct igc_adapter
> *adapter,
> if (qopt->base_time < 0)
> return -ERANGE;
>
> - if (igc_is_device_id_i225(hw) && adapter->base_time)
> + if (igc_is_device_id_i225(hw) && adapter->taprio_offload_enable)
> return -EALREADY;

I appreciate you catching that. Only i225 is affected by this; i226 is unaffected.

>
> if (!validate_schedule(adapter, qopt))
> --
> 2.39.2


Subject: RE: [PATCH net-next 0/6] igc: Fix corner cases for TSN offload



> -----Original Message-----
> From: Florian Kauer <[email protected]>
> Sent: Saturday, 17 June, 2023 12:11 AM
> To: Zulkifli, Muhammad Husaini <[email protected]>;
> Brandeburg, Jesse <[email protected]>; Nguyen, Anthony L
> <[email protected]>; Gomes, Vinicius <[email protected]>;
> David S . Miller <[email protected]>; Eric Dumazet
> <[email protected]>; Jakub Kicinski <[email protected]>; Paolo Abeni
> <[email protected]>; Tan Tee Min <[email protected]>;
> Gunasekaran, Aravindhan <[email protected]>; Chilakala,
> Mallikarjuna <[email protected]>
> Cc: [email protected]; [email protected]; linux-
> [email protected]; [email protected]
> Subject: Re: [PATCH net-next 0/6] igc: Fix corner cases for TSN offload
>
> On 16.06.23 17:53, Zulkifli, Muhammad Husaini wrote:
> >> Florian Kauer (6):
> >> igc: Rename qbv_enable to taprio_offload_enable
> >> igc: Do not enable taprio offload for invalid arguments
> >> igc: Handle already enabled taprio offload for basetime 0
> >> igc: No strict mode in pure launchtime/CBS offload
> >> igc: Fix launchtime before start of cycle
> >> igc: Fix inserting of empty frame for launchtime
> >
> > All six patches, as far as I can see here, have the Fixes tag. Should they go to
> Net instead of Net-Next?
>
> You are correct, these are all fixes and could go to net.
> However, in its current form they will not fully apply to net (e.g. due to the
> commit 2d800bc500fb ("net/sched: taprio: replace tc_taprio_qopt_offload ::
> enable with a "cmd" enum") that has overlapping code changes) and are also
> not tested with net.
> If you prefer to have them in net already I could send a second series.
> For me personally all options (net, net-next or iwl-next) would be fine.

Yeah I would prefer "net" so that it can be available in current development kernel.
"Net-next" will take sometimes to go in....
Looks like only patch no 2 "igc: Do not enable taprio offload for invalid arguments"
will have conflict due to the new "cmd" command introduced by vlamidir.
But I think should be minor changes.

Thanks

>
> Thanks,
> Florian