[PATCH v2 1/3] Bluetooth: btintel_pcie: Fix driver not posting maximum rx buffers

[PATCH v2 1/3] Bluetooth: btintel_pcie: Fix driver not posting maximum rx buffers

[Kiran K]

The driver was posting only 6 rx buffers, despite the maximum rx buffers
being defined as 16. Having fewer RX buffers caused firmware exceptions
in HID use cases when events arrived in bursts.

Exception seen on android 6.12 kernel.

E Bluetooth: hci0: Received hw exception interrupt
E Bluetooth: hci0: Received gp1 mailbox interrupt
D Bluetooth: hci0: 00000000: ff 3e 87 80 03 01 01 01 03 01 0c 0d 02 1c 10 0e
D Bluetooth: hci0: 00000010: 01 00 05 14 66 b0 28 b0 c0 b0 28 b0 ac af 28 b0
D Bluetooth: hci0: 00000020: 14 f1 28 b0 00 00 00 00 fa 04 00 00 00 00 40 10
D Bluetooth: hci0: 00000030: 08 00 00 00 7a 7a 7a 7a 47 00 fb a0 10 00 00 00
D Bluetooth: hci0: 00000000: 10 01 0a
E Bluetooth: hci0: ---- Dump of debug registers —
E Bluetooth: hci0: boot stage: 0xe0fb0047
E Bluetooth: hci0: ipc status: 0x00000004
E Bluetooth: hci0: ipc control: 0x00000000
E Bluetooth: hci0: ipc sleep control: 0x00000000
E Bluetooth: hci0: mbox_1: 0x00badbad
E Bluetooth: hci0: mbox_2: 0x0000101c
E Bluetooth: hci0: mbox_3: 0x00000008
E Bluetooth: hci0: mbox_4: 0x7a7a7a7a

Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Signed-off-by: Kiran K <kiran.k@intel.com>
Fixes: c2b636b3f788 ("Bluetooth: btintel_pcie: Add support for PCIe transport")
---
changes from v1->v2:
- Update commit message
- Add dmesg snipped related firmware exception

 drivers/bluetooth/btintel_pcie.c | 3 ++-
 drivers/bluetooth/btintel_pcie.h | 3 ---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
index 50fe17f1e1d1..2c7731803c9f 100644
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -396,8 +396,9 @@ static int btintel_pcie_submit_rx(struct btintel_pcie_data *data)
 static int btintel_pcie_start_rx(struct btintel_pcie_data *data)
 {
 	int i, ret;
+	struct rxq *rxq = &data->rxq;
 
-	for (i = 0; i < BTINTEL_PCIE_RX_MAX_QUEUE; i++) {
+	for (i = 0; i < rxq->count; i++) {
 		ret = btintel_pcie_submit_rx(data);
 		if (ret)
 			return ret;
diff --git a/drivers/bluetooth/btintel_pcie.h b/drivers/bluetooth/btintel_pcie.h
index 21b964b15c1c..5ddd6d7d8d45 100644
--- a/drivers/bluetooth/btintel_pcie.h
+++ b/drivers/bluetooth/btintel_pcie.h
@@ -177,9 +177,6 @@ enum {
 /* Doorbell vector for TFD */
 #define BTINTEL_PCIE_TX_DB_VEC	0
 
-/* Number of pending RX requests for downlink */
-#define BTINTEL_PCIE_RX_MAX_QUEUE	6
-
 /* Doorbell vector for FRBD */
 #define BTINTEL_PCIE_RX_DB_VEC	513
 
-- 
2.43.0

[PATCH v2 2/3] Bluetooth: btintel_pcie: Increase the tx and rx descriptor count

[Kiran K]

From: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>

This change addresses latency issues observed in HID use cases where
events arrive in bursts. By increasing the Rx descriptor count to 64,
the firmware can handle bursty data more effectively, reducing latency
and preventing buffer overflows.

Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Signed-off-by: Kiran K <kiran.k@intel.com>
---
 drivers/bluetooth/btintel_pcie.c | 24 ++++++++++++------------
 drivers/bluetooth/btintel_pcie.h |  7 +++++--
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
index 2c7731803c9f..03f13de4a723 100644
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -1783,8 +1783,8 @@ static int btintel_pcie_alloc(struct btintel_pcie_data *data)
 	 *  + size of index * Number of queues(2) * type of index array(4)
 	 *  + size of context information
 	 */
-	total = (sizeof(struct tfd) + sizeof(struct urbd0) + sizeof(struct frbd)
-		+ sizeof(struct urbd1)) * BTINTEL_DESCS_COUNT;
+	total = (sizeof(struct tfd) + sizeof(struct urbd0)) * BTINTEL_PCIE_TX_DESCS_COUNT;
+	total += (sizeof(struct frbd) + sizeof(struct urbd1)) * BTINTEL_PCIE_RX_DESCS_COUNT;
 
 	/* Add the sum of size of index array and size of ci struct */
 	total += (sizeof(u16) * BTINTEL_PCIE_NUM_QUEUES * 4) + sizeof(struct ctx_info);
@@ -1809,36 +1809,36 @@ static int btintel_pcie_alloc(struct btintel_pcie_data *data)
 	data->dma_v_addr = v_addr;
 
 	/* Setup descriptor count */
-	data->txq.count = BTINTEL_DESCS_COUNT;
-	data->rxq.count = BTINTEL_DESCS_COUNT;
+	data->txq.count = BTINTEL_PCIE_TX_DESCS_COUNT;
+	data->rxq.count = BTINTEL_PCIE_RX_DESCS_COUNT;
 
 	/* Setup tfds */
 	data->txq.tfds_p_addr = p_addr;
 	data->txq.tfds = v_addr;
 
-	p_addr += (sizeof(struct tfd) * BTINTEL_DESCS_COUNT);
-	v_addr += (sizeof(struct tfd) * BTINTEL_DESCS_COUNT);
+	p_addr += (sizeof(struct tfd) * BTINTEL_PCIE_TX_DESCS_COUNT);
+	v_addr += (sizeof(struct tfd) * BTINTEL_PCIE_TX_DESCS_COUNT);
 
 	/* Setup urbd0 */
 	data->txq.urbd0s_p_addr = p_addr;
 	data->txq.urbd0s = v_addr;
 
-	p_addr += (sizeof(struct urbd0) * BTINTEL_DESCS_COUNT);
-	v_addr += (sizeof(struct urbd0) * BTINTEL_DESCS_COUNT);
+	p_addr += (sizeof(struct urbd0) * BTINTEL_PCIE_TX_DESCS_COUNT);
+	v_addr += (sizeof(struct urbd0) * BTINTEL_PCIE_TX_DESCS_COUNT);
 
 	/* Setup FRBD*/
 	data->rxq.frbds_p_addr = p_addr;
 	data->rxq.frbds = v_addr;
 
-	p_addr += (sizeof(struct frbd) * BTINTEL_DESCS_COUNT);
-	v_addr += (sizeof(struct frbd) * BTINTEL_DESCS_COUNT);
+	p_addr += (sizeof(struct frbd) * BTINTEL_PCIE_RX_DESCS_COUNT);
+	v_addr += (sizeof(struct frbd) * BTINTEL_PCIE_RX_DESCS_COUNT);
 
 	/* Setup urbd1 */
 	data->rxq.urbd1s_p_addr = p_addr;
 	data->rxq.urbd1s = v_addr;
 
-	p_addr += (sizeof(struct urbd1) * BTINTEL_DESCS_COUNT);
-	v_addr += (sizeof(struct urbd1) * BTINTEL_DESCS_COUNT);
+	p_addr += (sizeof(struct urbd1) * BTINTEL_PCIE_RX_DESCS_COUNT);
+	v_addr += (sizeof(struct urbd1) * BTINTEL_PCIE_RX_DESCS_COUNT);
 
 	/* Setup data buffers for txq */
 	err = btintel_pcie_setup_txq_bufs(data, &data->txq);
diff --git a/drivers/bluetooth/btintel_pcie.h b/drivers/bluetooth/btintel_pcie.h
index 5ddd6d7d8d45..7dad4523236c 100644
--- a/drivers/bluetooth/btintel_pcie.h
+++ b/drivers/bluetooth/btintel_pcie.h
@@ -154,8 +154,11 @@ enum msix_mbox_int_causes {
 /* Default interrupt timeout in msec */
 #define BTINTEL_DEFAULT_INTR_TIMEOUT_MS	3000
 
-/* The number of descriptors in TX/RX queues */
-#define BTINTEL_DESCS_COUNT	16
+/* The number of descriptors in TX queues */
+#define BTINTEL_PCIE_TX_DESCS_COUNT	32
+
+/* The number of descriptors in RX queues */
+#define BTINTEL_PCIE_RX_DESCS_COUNT	64
 
 /* Number of Queue for TX and RX
  * It indicates the index of the IA(Index Array)
-- 
2.43.0

[PATCH v2 3/3] Bluetooth: btintel_pcie: Reduce driver buffer posting to prevent race condition

[Kiran K]

From: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>

Modify the driver to post 3 fewer buffers than the maximum rx buffers
(64) allowed for the firmware. This change mitigates a hardware issue
causing a race condition in the firmware, improving stability and data
handling.

Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Signed-off-by: Kiran K <kiran.k@intel.com>
---
changes from v1->v2:
- Add errata details

 drivers/bluetooth/btintel_pcie.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
index 03f13de4a723..780697880d59 100644
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -398,7 +398,12 @@ static int btintel_pcie_start_rx(struct btintel_pcie_data *data)
 	int i, ret;
 	struct rxq *rxq = &data->rxq;
 
-	for (i = 0; i < rxq->count; i++) {
+	/* WREQ-198603 - Post (BTINTEL_PCIE_RX_DESCS_COUNT - 3) buffers to
+	 * overcome the hardware issues leading to race condition at the
+	 * firmware.
+	 */
+
+	for (i = 0; i < rxq->count - 3; i++) {
 		ret = btintel_pcie_submit_rx(data);
 		if (ret)
 			return ret;
-- 
2.43.0

RE: [v2,1/3] Bluetooth: btintel_pcie: Fix driver not posting maximum rx buffers

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 1681 bytes --]

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=967825

---Test result---

Test Summary:
CheckPatch                    PENDING   0.21 seconds
GitLint                       PENDING   0.20 seconds
SubjectPrefix                 PASS      0.35 seconds
BuildKernel                   PASS      24.36 seconds
CheckAllWarning               PASS      26.61 seconds
CheckSparse                   PASS      29.99 seconds
BuildKernel32                 PASS      23.87 seconds
TestRunnerSetup               PASS      453.04 seconds
TestRunner_l2cap-tester       PASS      24.98 seconds
TestRunner_iso-tester         PASS      43.65 seconds
TestRunner_bnep-tester        PASS      5.80 seconds
TestRunner_mgmt-tester        PASS      146.57 seconds
TestRunner_rfcomm-tester      PASS      9.35 seconds
TestRunner_sco-tester         PASS      14.55 seconds
TestRunner_ioctl-tester       PASS      9.70 seconds
TestRunner_mesh-tester        PASS      7.22 seconds
TestRunner_smp-tester         PASS      8.44 seconds
TestRunner_userchan-tester    PASS      6.08 seconds
IncrementalBuild              PENDING   0.83 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH v2 1/3] Bluetooth: btintel_pcie: Fix driver not posting maximum rx buffers

[patchwork-bot+bluetooth]

Hello:

This series was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Sun,  1 Jun 2025 08:58:22 +0530 you wrote:
> The driver was posting only 6 rx buffers, despite the maximum rx buffers
> being defined as 16. Having fewer RX buffers caused firmware exceptions
> in HID use cases when events arrived in bursts.
> 
> Exception seen on android 6.12 kernel.
> 
> E Bluetooth: hci0: Received hw exception interrupt
> E Bluetooth: hci0: Received gp1 mailbox interrupt
> D Bluetooth: hci0: 00000000: ff 3e 87 80 03 01 01 01 03 01 0c 0d 02 1c 10 0e
> D Bluetooth: hci0: 00000010: 01 00 05 14 66 b0 28 b0 c0 b0 28 b0 ac af 28 b0
> D Bluetooth: hci0: 00000020: 14 f1 28 b0 00 00 00 00 fa 04 00 00 00 00 40 10
> D Bluetooth: hci0: 00000030: 08 00 00 00 7a 7a 7a 7a 47 00 fb a0 10 00 00 00
> D Bluetooth: hci0: 00000000: 10 01 0a
> E Bluetooth: hci0: ---- Dump of debug registers —
> E Bluetooth: hci0: boot stage: 0xe0fb0047
> E Bluetooth: hci0: ipc status: 0x00000004
> E Bluetooth: hci0: ipc control: 0x00000000
> E Bluetooth: hci0: ipc sleep control: 0x00000000
> E Bluetooth: hci0: mbox_1: 0x00badbad
> E Bluetooth: hci0: mbox_2: 0x0000101c
> E Bluetooth: hci0: mbox_3: 0x00000008
> E Bluetooth: hci0: mbox_4: 0x7a7a7a7a
> 
> [...]

Here is the summary with links:
  - [v2,1/3] Bluetooth: btintel_pcie: Fix driver not posting maximum rx buffers
    https://git.kernel.org/bluetooth/bluetooth-next/c/31b3d39c89f9
  - [v2,2/3] Bluetooth: btintel_pcie: Increase the tx and rx descriptor count
    https://git.kernel.org/bluetooth/bluetooth-next/c/e849b59c9db0
  - [v2,3/3] Bluetooth: btintel_pcie: Reduce driver buffer posting to prevent race condition
    (no matching commit)

You are awesome, thank you!
-- 
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