orinoco_usb: Use the regular completion interfaces

The completion usage in this driver is interesting:

  - it uses a magic complete function which according to the comment was
    implemented by invoking complete() four times in a row because
    complete_all() was not exported at that time.

  - it uses an open coded wait/poll which checks completion:done. Only one wait
    side (device removal) uses the regular wait_for_completion() interface.

The rationale behind this is to prevent that wait_for_completion() consumes
completion::done which would prevent that all waiters are woken. This is not
necessary with complete_all() as that sets completion::done to UINT_MAX which
is left unmodified by the woken waiters.

Replace the magic complete function with complete_all() and convert the
open coded wait/poll to regular completion interfaces.

This changes the wait to exclusive wait mode. But that does not make any
difference because the wakers use complete_all() which ignores the
exclusive mode.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/20200321113241.150783464@linutronix.de
This commit is contained in:
Thomas Gleixner 2020-03-21 12:25:48 +01:00 committed by Peter Zijlstra
parent c1d51dd505
commit 9fe114ce03

View file

@ -365,17 +365,6 @@ static struct request_context *ezusb_alloc_ctx(struct ezusb_priv *upriv,
return ctx;
}
/* Hopefully the real complete_all will soon be exported, in the mean
* while this should work. */
static inline void ezusb_complete_all(struct completion *comp)
{
complete(comp);
complete(comp);
complete(comp);
complete(comp);
}
static void ezusb_ctx_complete(struct request_context *ctx)
{
struct ezusb_priv *upriv = ctx->upriv;
@ -409,7 +398,7 @@ static void ezusb_ctx_complete(struct request_context *ctx)
netif_wake_queue(dev);
}
ezusb_complete_all(&ctx->done);
complete_all(&ctx->done);
ezusb_request_context_put(ctx);
break;
@ -419,7 +408,7 @@ static void ezusb_ctx_complete(struct request_context *ctx)
/* This is normal, as all request contexts get flushed
* when the device is disconnected */
err("Called, CTX not terminating, but device gone");
ezusb_complete_all(&ctx->done);
complete_all(&ctx->done);
ezusb_request_context_put(ctx);
break;
}
@ -690,11 +679,11 @@ static void ezusb_req_ctx_wait(struct ezusb_priv *upriv,
* get the chance to run themselves. So we make sure
* that we don't sleep for ever */
int msecs = DEF_TIMEOUT * (1000 / HZ);
while (!ctx->done.done && msecs--)
while (!try_wait_for_completion(&ctx->done) && msecs--)
udelay(1000);
} else {
wait_event_interruptible(ctx->done.wait,
ctx->done.done);
wait_for_completion(&ctx->done);
}
break;
default: