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SubjectRe: [PATCH v2] Bluetooth: hci_qca: Bug fixes while collecting controller memory dump
Hi Abhishek,

Sure I will update and post next patch set.

Regards,
Lakshmi Narayana.
On 2020-02-12 22:27, Abhishek Pandit-Subedi wrote:
> Hi Venkata,
>
> I would suggest removing the memdump_timer entirely and making the
> ctrl_memdump_timeout into struct delayed_work.
>
> Instead of using mod_timer to get the callback ready, you would
> instead call `queue_delayed_work(qca->workqueue,
> &qca->ctrl_memdump_timeout, MEMDUMP_TIMEOUT_MS);` and instead of
> del_timer, you would instead
> `cancel_delayed_work(&qca->ctrl_memdump_timeout)` if mutex is held or
> `cancel_delayed_work_sync(&qca->ctrl_memdump_timeout)` if mutex is not
> held.
>
> Other than that, everything else looks good to me.
>
> On Wed, Feb 12, 2020 at 7:51 AM Venkata Lakshmi Narayana Gubba
> <gubbaven@codeaurora.org> wrote:
>>
>> This patch will fix the below issues
>> 1.Fixed race conditions while accessing memory dump state flags.
>> 2.Updated with actual context of timer in hci_memdump_timeout()
>> 3.Updated injecting hardware error event if the dumps failed to
>> receive.
>> 4.Once timeout is triggered, stopping the memory dump collections.
>>
>> Possible scenarios while collecting memory dump:
>>
>> Scenario 1:
>>
>> Memdump event from firmware
>> Some number of memdump events with seq #
>> Hw error event
>> Reset
>>
>> Scenario 2:
>>
>> Memdump event from firmware
>> Some number of memdump events with seq #
>> Timeout schedules hw_error_event if hw error event is not received
>> already
>> hw_error_event clears the memdump activity
>> reset
>>
>> Scenario 3:
>>
>> hw_error_event sends memdump command to firmware and waits for
>> completion
>> Some number of memdump events with seq #
>> hw error event
>> reset
>>
>> Fixes: d841502c79e3 ("Bluetooth: hci_qca: Collect controller memory
>> dump during SSR")
>> Reported-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
>> Signed-off-by: Venkata Lakshmi Narayana Gubba
>> <gubbaven@codeaurora.org>
>> ---
>> drivers/bluetooth/hci_qca.c | 96
>> ++++++++++++++++++++++++++++++++-------------
>> 1 file changed, 69 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>> index eacc65b..80ee838 100644
>> --- a/drivers/bluetooth/hci_qca.c
>> +++ b/drivers/bluetooth/hci_qca.c
>> @@ -29,6 +29,7 @@
>> #include <linux/platform_device.h>
>> #include <linux/regulator/consumer.h>
>> #include <linux/serdev.h>
>> +#include <linux/mutex.h>
>> #include <asm/unaligned.h>
>>
>> #include <net/bluetooth/bluetooth.h>
>> @@ -69,7 +70,8 @@ enum qca_flags {
>> QCA_IBS_ENABLED,
>> QCA_DROP_VENDOR_EVENT,
>> QCA_SUSPENDING,
>> - QCA_MEMDUMP_COLLECTION
>> + QCA_MEMDUMP_COLLECTION,
>> + QCA_HW_ERROR_EVENT
>> };
>>
>>
>> @@ -145,11 +147,13 @@ struct qca_data {
>> struct work_struct ws_rx_vote_off;
>> struct work_struct ws_tx_vote_off;
>> struct work_struct ctrl_memdump_evt;
>> + struct work_struct ctrl_memdump_timeout;
>> struct qca_memdump_data *qca_memdump;
>> unsigned long flags;
>> struct completion drop_ev_comp;
>> wait_queue_head_t suspend_wait_q;
>> enum qca_memdump_states memdump_state;
>> + struct mutex hci_memdump_lock;
>>
>> /* For debugging purpose */
>> u64 ibs_sent_wacks;
>> @@ -524,21 +528,33 @@ static void hci_ibs_wake_retrans_timeout(struct
>> timer_list *t)
>>
>> static void hci_memdump_timeout(struct timer_list *t)
>> {
>> - struct qca_data *qca = from_timer(qca, t, tx_idle_timer);
>> - struct hci_uart *hu = qca->hu;
>> - struct qca_memdump_data *qca_memdump = qca->qca_memdump;
>> - char *memdump_buf = qca_memdump->memdump_buf_tail;
>> -
>> - bt_dev_err(hu->hdev, "clearing allocated memory due to memdump
>> timeout");
>> - /* Inject hw error event to reset the device and driver. */
>> - hci_reset_dev(hu->hdev);
>> - vfree(memdump_buf);
>> - kfree(qca_memdump);
>> - qca->memdump_state = QCA_MEMDUMP_TIMEOUT;
>> + struct qca_data *qca = from_timer(qca, t, memdump_timer);
>> +
>> + queue_work(qca->workqueue, &qca->ctrl_memdump_timeout);
>> del_timer(&qca->memdump_timer);
>> - cancel_work_sync(&qca->ctrl_memdump_evt);
>> }
>>
>> +static void qca_controller_memdump_timeout(struct work_struct *work)
>> +{
>> + struct qca_data *qca = container_of(work, struct qca_data,
>> + ctrl_memdump_timeout);
>> + struct hci_uart *hu = qca->hu;
>> +
>> + mutex_lock(&qca->hci_memdump_lock);
>> + if (test_bit(QCA_MEMDUMP_COLLECTION, &qca->flags)) {
>> + qca->memdump_state = QCA_MEMDUMP_TIMEOUT;
>> + if (!test_bit(QCA_HW_ERROR_EVENT, &qca->flags)) {
>> + /* Inject hw error event to reset the device
>> + * and driver.
>> + */
>> + hci_reset_dev(hu->hdev);
>> + }
>> + }
>> +
>> + mutex_unlock(&qca->hci_memdump_lock);
>> +}
>> +
>> +
>> /* Initialize protocol */
>> static int qca_open(struct hci_uart *hu)
>> {
>> @@ -558,6 +574,7 @@ static int qca_open(struct hci_uart *hu)
>> skb_queue_head_init(&qca->tx_wait_q);
>> skb_queue_head_init(&qca->rx_memdump_q);
>> spin_lock_init(&qca->hci_ibs_lock);
>> + mutex_init(&qca->hci_memdump_lock);
>> qca->workqueue = alloc_ordered_workqueue("qca_wq", 0);
>> if (!qca->workqueue) {
>> BT_ERR("QCA Workqueue not initialized properly");
>> @@ -570,6 +587,7 @@ static int qca_open(struct hci_uart *hu)
>> INIT_WORK(&qca->ws_rx_vote_off,
>> qca_wq_serial_rx_clock_vote_off);
>> INIT_WORK(&qca->ws_tx_vote_off,
>> qca_wq_serial_tx_clock_vote_off);
>> INIT_WORK(&qca->ctrl_memdump_evt, qca_controller_memdump);
>> + INIT_WORK(&qca->ctrl_memdump_timeout,
>> qca_controller_memdump_timeout);
>> init_waitqueue_head(&qca->suspend_wait_q);
>>
>> qca->hu = hu;
>> @@ -963,11 +981,20 @@ static void qca_controller_memdump(struct
>> work_struct *work)
>>
>> while ((skb = skb_dequeue(&qca->rx_memdump_q))) {
>>
>> + mutex_lock(&qca->hci_memdump_lock);
>> + /* Skip processing the received packets if timeout
>> detected. */
>> + if (qca->memdump_state == QCA_MEMDUMP_TIMEOUT) {
>> + mutex_unlock(&qca->hci_memdump_lock);
>> + return;
>> + }
>> +
>> if (!qca_memdump) {
>> qca_memdump = kzalloc(sizeof(struct
>> qca_memdump_data),
>> GFP_ATOMIC);
>> - if (!qca_memdump)
>> + if (!qca_memdump) {
>> + mutex_unlock(&qca->hci_memdump_lock);
>> return;
>> + }
>>
>> qca->qca_memdump = qca_memdump;
>> }
>> @@ -992,6 +1019,7 @@ static void qca_controller_memdump(struct
>> work_struct *work)
>> if (!(dump_size)) {
>> bt_dev_err(hu->hdev, "Rx invalid
>> memdump size");
>> kfree_skb(skb);
>> + mutex_unlock(&qca->hci_memdump_lock);
>> return;
>> }
>>
>> @@ -1016,6 +1044,7 @@ static void qca_controller_memdump(struct
>> work_struct *work)
>> kfree(qca_memdump);
>> kfree_skb(skb);
>> qca->qca_memdump = NULL;
>> + mutex_unlock(&qca->hci_memdump_lock);
>> return;
>> }
>>
>> @@ -1050,12 +1079,16 @@ static void qca_controller_memdump(struct
>> work_struct *work)
>> kfree(qca->qca_memdump);
>> qca->qca_memdump = NULL;
>> qca->memdump_state = QCA_MEMDUMP_COLLECTED;
>> + clear_bit(QCA_MEMDUMP_COLLECTION,
>> &qca->flags);
>> }
>> +
>> + mutex_unlock(&qca->hci_memdump_lock);
>> }
>>
>> }
>>
>> -int qca_controller_memdump_event(struct hci_dev *hdev, struct sk_buff
>> *skb)
>> +static int qca_controller_memdump_event(struct hci_dev *hdev,
>> + struct sk_buff *skb)
>> {
>> struct hci_uart *hu = hci_get_drvdata(hdev);
>> struct qca_data *qca = hu->priv;
>> @@ -1406,30 +1439,21 @@ static void
>> qca_wait_for_dump_collection(struct hci_dev *hdev)
>> {
>> struct hci_uart *hu = hci_get_drvdata(hdev);
>> struct qca_data *qca = hu->priv;
>> - struct qca_memdump_data *qca_memdump = qca->qca_memdump;
>> - char *memdump_buf = NULL;
>>
>> wait_on_bit_timeout(&qca->flags, QCA_MEMDUMP_COLLECTION,
>> TASK_UNINTERRUPTIBLE, MEMDUMP_TIMEOUT_MS);
>>
>> clear_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
>> - if (qca->memdump_state == QCA_MEMDUMP_IDLE) {
>> - bt_dev_err(hu->hdev, "Clearing the buffers due to
>> timeout");
>> - if (qca_memdump)
>> - memdump_buf = qca_memdump->memdump_buf_tail;
>> - vfree(memdump_buf);
>> - kfree(qca_memdump);
>> - qca->memdump_state = QCA_MEMDUMP_TIMEOUT;
>> - del_timer(&qca->memdump_timer);
>> - cancel_work_sync(&qca->ctrl_memdump_evt);
>> - }
>> }
>>
>> static void qca_hw_error(struct hci_dev *hdev, u8 code)
>> {
>> struct hci_uart *hu = hci_get_drvdata(hdev);
>> struct qca_data *qca = hu->priv;
>> + struct qca_memdump_data *qca_memdump = qca->qca_memdump;
>> + char *memdump_buf = NULL;
>>
>> + set_bit(QCA_HW_ERROR_EVENT, &qca->flags);
>> bt_dev_info(hdev, "mem_dump_status: %d", qca->memdump_state);
>>
>> if (qca->memdump_state == QCA_MEMDUMP_IDLE) {
>> @@ -1449,6 +1473,24 @@ static void qca_hw_error(struct hci_dev *hdev,
>> u8 code)
>> bt_dev_info(hdev, "waiting for dump to complete");
>> qca_wait_for_dump_collection(hdev);
>> }
>> +
>> + if (qca->memdump_state != QCA_MEMDUMP_COLLECTED) {
>> + bt_dev_err(hu->hdev, "clearing allocated memory due to
>> memdump timeout");
>> + mutex_lock(&qca->hci_memdump_lock);
>> + if (qca_memdump)
>> + memdump_buf = qca_memdump->memdump_buf_head;
>> + vfree(memdump_buf);
>> + kfree(qca_memdump);
>> + qca->qca_memdump = NULL;
>> + qca->memdump_state = QCA_MEMDUMP_TIMEOUT;
>> + del_timer(&qca->memdump_timer);
>> + skb_queue_purge(&qca->rx_memdump_q);
>> + mutex_unlock(&qca->hci_memdump_lock);
>> + cancel_work_sync(&qca->ctrl_memdump_timeout);
>> + cancel_work_sync(&qca->ctrl_memdump_evt);
>> + }
>> +
>> + clear_bit(QCA_HW_ERROR_EVENT, &qca->flags);
>> }
>>
>> static void qca_cmd_timeout(struct hci_dev *hdev)
>> --
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
>> member
>> of Code Aurora Forum, hosted by The Linux Foundation
>>
>
> Thanks
> Abhishek

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