| Message ID | 20240228-multi_waitq-v1-1-ccb096419af0@quicinc.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | SCM: Support latest version of waitq-aware firmware | expand |
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 > >
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; - init_completion(&__scm->waitq_comp); - irq = platform_get_irq_optional(pdev, 0); if (irq < 0) { if (irq != -ENXIO)
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(-)