From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: [patch V3 04/20] orinoco_usb: Use the regular completion interfaces Date: Sat, 21 Mar 2020 12:25:48 +0100 Message-ID: <20200321113241.150783464@linutronix.de> References: <20200321112544.878032781@linutronix.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8-bit Return-path: Sender: linux-acpi-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: LKML Cc: Peter Zijlstra , Ingo Molnar , Sebastian Siewior , Linus Torvalds , Joel Fernandes , Oleg Nesterov , Davidlohr Bueso , Greg Kroah-Hartman , Kalle Valo , "David S. Miller" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, Logan Gunthorpe , Bjorn Helgaas , Kurt Schwemmer , linux-pci@vger.kernel.org, Felipe Balbi , Darren Hart , Andy Shevchenko , platform-driver-x86@vg From: Thomas Gleixner 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 Signed-off-by: Thomas Gleixner Reviewed-by: Greg Kroah-Hartman Cc: Kalle Valo Cc: "David S. Miller" Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-usb@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; default: