2018-05-29 16:37:16

by Thierry Escande

Subject: [PATCH] Bluetooth: hci_qca: Fix "Sleep inside atomic section" warning

This patch fixes the following warning during boot:

do not call blocking ops when !TASK_RUNNING; state=1 set at
[<(ptrval)>] qca_setup+0x194/0x750 [hci_uart]
WARNING: CPU: 2 PID: 1878 at kernel/sched/core.c:6135
__might_sleep+0x7c/0x88

In qca_set_baudrate(), the current task state is set to
TASK_UNINTERRUPTIBLE before going to sleep for 300ms. It was then
restored to TASK_INTERRUPTIBLE. This patch sets the current task state
back to TASK_RUNNING instead.

Signed-off-by: Thierry Escande <[email protected]>
---
drivers/bluetooth/hci_qca.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index f05382b5a65d..51790dd02afb 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -910,7 +910,7 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
*/
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS));
- set_current_state(TASK_INTERRUPTIBLE);
+ set_current_state(TASK_RUNNING);

return 0;
}
--
2.14.1

2018-05-30 06:13:35

by Marcel Holtmann

Subject: Re: [PATCH] Bluetooth: hci_qca: Fix "Sleep inside atomic section" warning

Hi Thierry,

> This patch fixes the following warning during boot:
>
> do not call blocking ops when !TASK_RUNNING; state=1 set at
> [<(ptrval)>] qca_setup+0x194/0x750 [hci_uart]
> WARNING: CPU: 2 PID: 1878 at kernel/sched/core.c:6135
> __might_sleep+0x7c/0x88
>
> In qca_set_baudrate(), the current task state is set to
> TASK_UNINTERRUPTIBLE before going to sleep for 300ms. It was then
> restored to TASK_INTERRUPTIBLE. This patch sets the current task state
> back to TASK_RUNNING instead.
>
> Signed-off-by: Thierry Escande <[email protected]>
> ---
> drivers/bluetooth/hci_qca.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

patch has been applied to bluetooth-next tree.

> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index f05382b5a65d..51790dd02afb 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -910,7 +910,7 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
> */
> set_current_state(TASK_UNINTERRUPTIBLE);
> schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS));
> - set_current_state(TASK_INTERRUPTIBLE);
> + set_current_state(TASK_RUNNING);
>

However wouldn’t it better to use msleep or similar instead of open coding it with schedule_timeout?

Regards

Marcel