On Fri, Jun 06, 2025 at 09:35:44AM -0400, Sinan Kaya wrote: > > On 6/5/2025 9:04 AM, Eugen Hristev wrote: > > > diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c > > > index fee448499777..0c2bae46746c 100644 > > > --- a/drivers/dma/qcom/hidma_ll.c > > > +++ b/drivers/dma/qcom/hidma_ll.c > > > @@ -816,6 +816,7 @@ int hidma_ll_uninit(struct hidma_lldev *lldev) > > > required_bytes = sizeof(struct hidma_tre) * lldev->nr_tres; > > > tasklet_kill(&lldev->task); > > > + kfifo_free(&lldev->handoff_fifo); > > > memset(lldev->trepool, 0, required_bytes); > > > lldev->trepool = NULL; > > > atomic_set(&lldev->pending_tre_count, 0); > > Is it possible that the handoff_fifo is freed, then we could observe > > reset complete interrupts before they are being cleared in > > hidma_ll_uninit later on, which would lead to the following call chain > > > > hidma_ll_inthandler - hidma_ll_int_handler_internal - > > hidma_handle_tre_completion - hidma_post_completed - > > tasklet_schedule(&lldev->task); - hidma_ll_tre_complete - kfifo_out > > According to the documentation, the way to guarantee this from not happening > > is to call tasklet_disable() to ensure that tasklet completes execution. > Only after that > > data structures used by the tasklet can be freed. > > I think proper order is: > > 1. tasklet_disable > > 2. tasklet_kill > > 3. kfifo_free Hi Sinan, hi Eugen, Thanks for reviewing the patch and for pointing out the correct shutdown ordering. If you’re both happy with it, I’ll send a v2 that calls tasklet_disable() before tasklet_kill(), then frees the handoff_fifo. Just let me know and I’ll resend. Thanks Qasim > > >
