LinuxLists.cc - [PATCH] Bluetooth: hci_h5: Complements reliable packet processing logic.

2023-04-03 16:50:58

Subject: [PATCH] Bluetooth: hci_h5: Complements reliable packet processing logic.

As shown in the schematic diagram below.There may be a critical
scenario in the current code. If the device does not receive an
pure ack sent by the host due to insufficient receive buffer or
other reasons and triggers a retransmission, the host will always
be in an 'out-of-order' state.The state machine will get stuck.

host device
SEQ3,ACK4 --------->
<--------- SEQ4,ACK4
pure ACK ---------> (not received)
(out-of-order) <--------- SEQ4,ACK4(retransmission)
........
(out-of-order) <--------- SEQ4,ACK4(retransmission)

According to the description in the core specification: "whenever
a reliable packet is received, an acknowledgment shall be generated."
we should set H5_TX_ACK_REQ bit to trigger retransmission of pure ack
packet when "out-of-order" occurs.

Signed-off-by: Qiqi Zhang <[email protected]>
---
drivers/bluetooth/hci_h5.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index 6455bc4fb5bb..d05eaeaa4516 100644
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -463,6 +463,8 @@ static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)",
H5_HDR_SEQ(hdr), h5->tx_ack);
+ set_bit(H5_TX_ACK_REQ, &h5->flags);
+ hci_uart_tx_wakeup(hu);
h5_reset_rx(h5);
return 0;
}
--
2.25.1

2023-04-03 17:38:45

by bluez.test.bot

[permalink] [raw]

Subject: RE: Bluetooth: hci_h5: Complements reliable packet processing logic.

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=736467

---Test result---

Test Summary:
CheckPatch PASS 0.60 seconds
GitLint FAIL 0.69 seconds
SubjectPrefix PASS 0.07 seconds
BuildKernel PASS 40.98 seconds
CheckAllWarning PASS 44.42 seconds
CheckSparse PASS 50.07 seconds
CheckSmatch PASS 137.54 seconds
BuildKernel32 PASS 39.45 seconds
TestRunnerSetup PASS 569.34 seconds
TestRunner_l2cap-tester PASS 19.17 seconds
TestRunner_iso-tester PASS 20.88 seconds
TestRunner_bnep-tester PASS 6.83 seconds
TestRunner_mgmt-tester PASS 132.76 seconds
TestRunner_rfcomm-tester PASS 10.48 seconds
TestRunner_sco-tester PASS 9.60 seconds
TestRunner_ioctl-tester PASS 11.50 seconds
TestRunner_mesh-tester PASS 8.51 seconds
TestRunner_smp-tester PASS 9.61 seconds
TestRunner_userchan-tester PASS 7.11 seconds
IncrementalBuild PASS 37.38 seconds

Details
##############################
Test: GitLint - FAIL
Desc: Run gitlint
Output:
Bluetooth: hci_h5: Complements reliable packet processing logic.

WARNING: I3 - ignore-body-lines: gitlint will be switching from using Python regex 'match' (match beginning) to 'search' (match anywhere) semantics. Please review your ignore-body-lines.regex option accordingly. To remove this warning, set general.regex-style-search=True. More details: https://jorisroovers.github.io/gitlint/configuration/#regex-style-search
1: T3 Title has trailing punctuation (.): "Bluetooth: hci_h5: Complements reliable packet processing logic."
14: B3 Line contains hard tab characters (\t): " ........"

---
Regards,
Linux Bluetooth

2023-04-04 02:33:02

by Qiqi Zhang

[permalink] [raw]

Subject: [PATCH v2] Bluetooth: hci_h5: Complements reliable packet processing logic

As shown in the schematic diagram below.There may be a critical
scenario in the current code. If the device does not receive an
pure ack sent by the host due to insufficient receive buffer or
other reasons and triggers a retransmission, the host will always
be in an 'out-of-order' state.The state machine will get stuck.

host device
SEQ3,ACK4 --------->
<--------- SEQ4,ACK4
pure ACK ---------> (not received)
(out-of-order) <--------- SEQ4,ACK4(retransmission)
........
(out-of-order) <--------- SEQ4,ACK4(retransmission)

According to the description in the core specification: "whenever
a reliable packet is received, an acknowledgment shall be generated."
So set H5_TX_ACK_REQ bit to trigger retransmission of pure ack packet
when "out-of-order" occurs.

Signed-off-by: Qiqi Zhang <[email protected]>
---
Changes in v2:
- Fixed build bot warning.
---
---
drivers/bluetooth/hci_h5.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index 6455bc4fb5bb..d05eaeaa4516 100644
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -463,6 +463,8 @@ static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)",
H5_HDR_SEQ(hdr), h5->tx_ack);
+ set_bit(H5_TX_ACK_REQ, &h5->flags);
+ hci_uart_tx_wakeup(hu);
h5_reset_rx(h5);
return 0;
}
--
2.25.1

2023-04-04 03:10:23

by bluez.test.bot

[permalink] [raw]

Subject: RE: [v2] Bluetooth: hci_h5: Complements reliable packet processing logic

2023-04-06 21:09:00

by patchwork-bot+bluetooth

[permalink] [raw]

Subject: Re: [PATCH v2] Bluetooth: hci_h5: Complements reliable packet processing logic

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <[email protected]>:

On Tue, 4 Apr 2023 10:27:11 +0800 you wrote:
> As shown in the schematic diagram below.There may be a critical
> scenario in the current code. If the device does not receive an
> pure ack sent by the host due to insufficient receive buffer or
> other reasons and triggers a retransmission, the host will always
> be in an 'out-of-order' state.The state machine will get stuck.
>
> host device
> SEQ3,ACK4 --------->
> <--------- SEQ4,ACK4
> pure ACK ---------> (not received)
> (out-of-order) <--------- SEQ4,ACK4(retransmission)
> ........
> (out-of-order) <--------- SEQ4,ACK4(retransmission)
>
> [...]

Here is the summary with links:
- [v2] Bluetooth: hci_h5: Complements reliable packet processing logic
https://git.kernel.org/bluetooth/bluetooth-next/c/13a6ebae665d

You are awesome, thank you!
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