From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755839Ab0KQFn2 (ORCPT ); Wed, 17 Nov 2010 00:43:28 -0500 Received: from mail-qw0-f46.google.com ([209.85.216.46]:43774 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753642Ab0KQFn1 convert rfc822-to-8bit (ORCPT ); Wed, 17 Nov 2010 00:43:27 -0500 MIME-Version: 1.0 X-Originating-IP: [192.163.20.232] In-Reply-To: References: <1289394446-14021-1-git-send-email-pavan_savoy@ti.com> <20101116225418.GA15101@vigoh> Date: Wed, 17 Nov 2010 11:13:26 +0530 Message-ID: Subject: Re: [PATCH v5] Bluetooth: btwilink driver From: Pavan Savoy To: Vitaly Wool Cc: "Gustavo F. Padovan" , marcel@holtmann.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 17, 2010 at 4:50 AM, Vitaly Wool wrote: >>> +     /* Registration with ST layer is successful, >>> +      * hardware is ready to accept commands from HCI core. >>> +      */ >>> +     if (test_and_set_bit(HCI_RUNNING, &hdev->flags)) { >>> +             clear_bit(HCI_RUNNING, &hdev->flags); >>> +             err = st_unregister(ST_BT); >>> +             if (err) >>> +                     BT_ERR("st_unregister() failed with error %d", err); >>> +             hst->st_write = NULL; >>> +     } >> >> >> What are you trying to do here? test_and_set_bit() result doesn't say >> nothing about error and you shall put test_and_set_bit should be in the >> beginning, to know if your device is already opened or not and then >> clear_bit if some error ocurrs during the function. >> > > Yeap, this piece of code beats me is well. Why is it an error if this > bit wasn't already set? Vitaly, Gustavo, I suppose I never understood HCI_RUNNING flag that way, as in an error check mechanism to avoid multiple hci0 ups. What I understood was that HCI_RUNNING suggested as to when hci0 was ready to be used. With this understanding, I wanted to make sure I downloaded the firmware for the chip before I proclaim to the world that the hci0 is ready to be used, as in HCI_RUNNING. For example, I didn't want my _send_frame to be called before I did the firmware download - since firmware download takes time - 45kb send/wait commands :( But I suppose I now understand - What I would rather do is test_bit in the beginning of function and do a set_bit at the end of function - does this make sense ? > ~Vitaly > -- > To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html >