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

diff --git a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
index e753f43e0162f109c35b8d0b4a712462e276bd6f..0e42de29180366aa0470ae5160be9d1465967b17 100644 (file)
--- a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
+++ b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c
@@ -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: