Return-path: Received: from mail-bk0-f42.google.com ([209.85.214.42]:49770 "EHLO mail-bk0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752462Ab3HENbd convert rfc822-to-8bit (ORCPT ); Mon, 5 Aug 2013 09:31:33 -0400 Received: by mail-bk0-f42.google.com with SMTP id jk14so988402bkc.29 for ; Mon, 05 Aug 2013 06:31:32 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1375430329-23352-1-git-send-email-bartosz.markowski@tieto.com> References: <1375430329-23352-1-git-send-email-bartosz.markowski@tieto.com> Date: Mon, 5 Aug 2013 15:31:31 +0200 Message-ID: (sfid-20130805_153138_270771_2B446A97) Subject: Re: [PATCH v2] ath10k: add SoC power save option to PCI features map From: Michal Kazior To: Bartosz Markowski Cc: ath10k@lists.infradead.org, linux-wireless@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2 August 2013 09:58, Bartosz Markowski wrote: > Unify the PCI options location. > > By default the SoC PS option is disabled to boost the > performance and due to poor stability on early HW revisions. > In future we can remove the module parameter and turn on/off > the PS for given hardware. > > This change also makes the pci module parameter for SoC PS static. > > Signed-off-by: Bartosz Markowski Hmm.. I'm worried about pci wake/sleep locking: (a) pci_wake() (awake count =1) (a) do something Now, if pci_sleep() and pci_wake() happen simultaneously/are preempted splitting primitive operations to: (a) pci_sleep(): decrease awake count (=0) (b) pci_wake(): increase awake count (=1), iowrite, wait for awake, return (a) pci_sleep(): iowrite(). return The flow in (b) now thinks the device is awake, but it's not guaranteed to be anymore because it has been put to sleep by (a). Pozdrawiam / Best regards, Michał Kazior.