Re: [PATCHv2] media: venc: destroy hfi session after m2m_ctx release

From: Dmitry Baryshkov
Date: Thu Dec 19 2024 - 08:13:08 EST


On Thu, Dec 19, 2024 at 02:37:08PM +0900, Sergey Senozhatsky wrote:
> This partially reverts commit that made hfi_session_destroy()
> the first step of vdec/venc close(). The reason being is a
> regression report when, supposedly, encode/decoder is closed
> with still active streaming (no ->stop_streaming() call before
> close()) and pending pkts, so isr_thread cannot find instance
> and fails to process those pending pkts. This was the idea
> behind the original patch - make it impossible to use instance
> under destruction, because this is racy, but apparently there
> are uses cases that depend on that unsafe pattern. Return to
> the old (unsafe) behaviour for the time being (until a better
> fix is found).

You are describing a regression. Could you please add corresponding
Reported-by and Closes tags (for now you can post them in a reply to
your patch, in future please include them in your commit message).

>
> Fixes: 45b1a1b348ec ("media: venus: sync with threaded IRQ during inst destruction")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>

This is v2, but there is no changelog. Please provide one.

Also please don't post your patches as replies to the previous versions.

> ---
> drivers/media/platform/qcom/venus/core.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c
> index 2d27c5167246..807487a1f536 100644
> --- a/drivers/media/platform/qcom/venus/core.c
> +++ b/drivers/media/platform/qcom/venus/core.c
> @@ -506,18 +506,14 @@ static __maybe_unused int venus_runtime_suspend(struct device *dev)
> void venus_close_common(struct venus_inst *inst)
> {
> /*
> - * First, remove the inst from the ->instances list, so that
> - * to_instance() will return NULL.
> - */
> - hfi_session_destroy(inst);
> - /*
> - * Second, make sure we don't have IRQ/IRQ-thread currently running
> + * Make sure we don't have IRQ/IRQ-thread currently running
> * or pending execution, which would race with the inst destruction.
> */
> synchronize_irq(inst->core->irq);
>
> v4l2_m2m_ctx_release(inst->m2m_ctx);
> v4l2_m2m_release(inst->m2m_dev);
> + hfi_session_destroy(inst);
> v4l2_fh_del(&inst->fh);
> v4l2_fh_exit(&inst->fh);
> v4l2_ctrl_handler_free(&inst->ctrl_handler);
> --
> 2.47.1.613.gc27f4b7a9f-goog
>

--
With best wishes
Dmitry