[patch V2 04/15] orinoco_usb: Use the regular completion interfaces

Thomas Gleixner
2020-03-18T20:47:20Z

From: Thomas Gleixner <tglx@linutronix.de>

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>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
---
V2: New patch to avoid conversion to swait functions later.
---
drivers/net/wireless/intersil/orinoco/orinoco_usb.c | 21 ++++----------------
1 file changed, 5 insertions(+), 16 deletions(-)

--- 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_all
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 re

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 re
/* 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 ez
* 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;