On Wed, Feb 28, 2024 at 7:50 PM Unnathi Chalicheemala
<quic_uchalich@quicinc.com> wrote:
>
> Suppose there's another device probing at the same time as SCM driver.
> It calls into SCM and triggers WAITQ sleep but waitq completion
> structure may not be initialized yet.
> Fix this by moving initialization of waitq before setting global __scm.
>
> Fixes: 6bf325992236 ("firmware: qcom: scm: Add wait-queue handling logic")
> Signed-off-by: Unnathi Chalicheemala <quic_uchalich@quicinc.com>
> ---
> drivers/firmware/qcom/qcom_scm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
> index 520de9b5633a..c1be8270ead1 100644
> --- a/drivers/firmware/qcom/qcom_scm.c
> +++ b/drivers/firmware/qcom/qcom_scm.c
> @@ -1854,11 +1854,11 @@ static int qcom_scm_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + init_completion(&scm->waitq_comp);
> +
> __scm = scm;
> __scm->dev = &pdev->dev;
If another driver can actually probe at the same time then this needs
to be moved to the end of this function, the `__scm->dev` assignment
must be done before the `__scm = scm` one and it must use
WRITE_ONCE().
Bart
>
> - init_completion(&__scm->waitq_comp);
> -
> irq = platform_get_irq_optional(pdev, 0);
> if (irq < 0) {
> if (irq != -ENXIO)
>
> --
> 2.25.1
>
>