From: Marcel Holtmann <marcel@holtmann.org>
To: Balakrishna Godavarthi <bgodavar@codeaurora.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>,
Matthias Kaehlcke <mka@chromium.org>,
open list <linux-kernel@vger.kernel.org>,
"open list:BLUETOOTH SUBSYSTEM" <linux-bluetooth@vger.kernel.org>,
Hemantg <hemantg@codeaurora.org>,
MSM <linux-arm-msm@vger.kernel.org>,
pharish@codeaurora.org, Rocky Liao <rjliao@codeaurora.org>,
hbandi@codeaurora.org,
Abhishek Pandit-Subedi <abhishekpandit@chromium.org>,
mcchou@chromium.org
Subject: Re: [PATCH] Bluetooth: hci_qca: Set SSR triggered flags when SSR command is sent out
Date: Thu, 19 Aug 2021 17:03:09 +0200 [thread overview]
Message-ID: <6238C7AB-32D7-4D12-A14E-24D12A862405@holtmann.org> (raw)
In-Reply-To: <086f2add931ff541c8a6349767ae2adc@codeaurora.org>
Hi Balakrishna,
>>> This change sets SSR triggered flags when QCA SSR command is sent to
>>> SoC. After the SSR command sent, driver discards the incoming data from
>>> the upper layers. This way will ensure to read full dumps from the
>>> BT SoC without any flow control issues due to excess of data receiving
>>> from the HOST in audio usecases.
>>> Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
>>> ---
>>> drivers/bluetooth/hci_qca.c | 10 ++++++++++
>>> 1 file changed, 10 insertions(+)
>>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>>> index 53deea2..5cbed6a 100644
>>> --- a/drivers/bluetooth/hci_qca.c
>>> +++ b/drivers/bluetooth/hci_qca.c
>>> @@ -69,6 +69,8 @@
>>> #define QCA_LAST_SEQUENCE_NUM 0xFFFF
>>> #define QCA_CRASHBYTE_PACKET_LEN 1096
>>> #define QCA_MEMDUMP_BYTE 0xFB
>>> +#define QCA_SSR_OPCODE 0xFC0C
>>> +#define QCA_SSR_PKT_LEN 5
>>> enum qca_flags {
>>> QCA_IBS_DISABLED,
>>> @@ -871,6 +873,14 @@ static int qca_enqueue(struct hci_uart *hu, struct sk_buff *skb)
>>> /* Prepend skb with frame type */
>>> memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
>>> + if (hci_skb_pkt_type(skb) == HCI_COMMAND_PKT &&
>>> + skb->len == QCA_SSR_PKT_LEN &&
>>> + hci_skb_opcode(skb) == QCA_SSR_OPCODE) {
>>> + bt_dev_info(hu->hdev, "Triggering ssr");
>>> + set_bit(QCA_SSR_TRIGGERED, &qca->flags);
>>> + set_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
>>> + }
>>> +
>> can we please stop hacking around by parsing opcodes in an enqueue
>> function. Sounds like someone is injecting raw HCI vendor commands and
>> then having a driver react to it.
> [Bala]: yes this opcode is injected via hcitool to test BT SoC dump procedure or
> to collect the dumps to debug the issue during issue cases. When audio usecases are running,
> HOST sends ACL packets to SoC, in meantime if this command is sent to SoC using hcitool
> to collect dumps at particular point, With out this check HOST is pumping continues data to
> SoC and SoC RFR line goes high, sometimes SoC become unresponsive and driver starts logging
> command timeout error. Instead here, once a cmd with this opcode is sent, timer is started
> to ensure that SSR is in progress. If no response from SoC for 8 seconds. Driver will be restarted.
so why would I add a kernel work-around for this?
Design a proper interface for this and don’t rely on injecting HCI commands via HCI raw channel.
Regards
Marcel
prev parent reply other threads:[~2021-08-19 15:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 5:21 [PATCH] Bluetooth: hci_qca: Set SSR triggered flags when SSR command is sent out Balakrishna Godavarthi
2021-08-16 16:07 ` Marcel Holtmann
2021-08-17 11:20 ` bgodavar
2021-08-19 15:03 ` Marcel Holtmann [this message]
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