Hi,
On Wed, Sep 04, 2024 at 06:07:20PM +0200, Takashi Iwai wrote:
> On Wed, 04 Sep 2024 14:51:51 +0200,
> Takashi Sakamoto wrote:
> >
> > In the previous commit, the workqueue is added per the instance of fw_card
> > structure for isochronous contexts. The workqueue is designed to be used by
> > the implementation of fw_card_driver structure underlying the fw_card.
> >
> > This commit adds some local APIs to be used by the implementation.
> >
> > Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
> > ---
> > drivers/firewire/core-iso.c | 30 ++++++++++++++++++++++++++++--
> > drivers/firewire/core.h | 10 ++++++++++
> > include/linux/firewire.h | 1 +
> > 3 files changed, 39 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
> > index 101433b8bb51..af76fa1823f1 100644
> > --- a/drivers/firewire/core-iso.c
> > +++ b/drivers/firewire/core-iso.c
> > @@ -211,21 +211,47 @@ EXPORT_SYMBOL(fw_iso_context_queue_flush);
> >
> > int fw_iso_context_flush_completions(struct fw_iso_context *ctx)
> > {
> > + int err;
> > +
> > trace_isoc_outbound_flush_completions(ctx);
> > trace_isoc_inbound_single_flush_completions(ctx);
> > trace_isoc_inbound_multiple_flush_completions(ctx);
> >
> > - return ctx->card->driver->flush_iso_completions(ctx);
> > + might_sleep();
> > +
> > + // Avoid dead lock due to programming mistake.
> > + if (WARN_ON(current_work() == &ctx->work))
> > + return 0;
>
> Maybe WARN_ON_ONCE() would be safer if it's supposed to be called
> frequently. Otherwise it can spam too much.
> Ditto for fw_iso_context_stop().
Thanks for your suggestion. Indeed, the kernel API would be called so
frequently, and the *_ONCE macro would be safer. I'll post another patch
for it, since posting updated series of changes to all of receivers is a
bit cumbersome to me...
Thanks
Takashi Sakamoto
