Date: Tue, 6 Dec 2005 10:37:29 -0200
From: Luiz Fernando Capitulino <lcapitulino@mandriva.com.br>
To: Arjan van de Ven <arjan@infradead.org>
Cc: gregkh@suse.de, linux-kernel@vger.kernel.org,
       linux-usb-devel@lists.sourceforge.net, ehabkost@mandriva.com
Subject: Re: [PATCH 01/10] usb-serial: URB write locking macros.
Message-Id: <20051206103729.6c4ee2b7.lcapitulino@mandriva.com.br>
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 Hi Arjan,

On Tue, 06 Dec 2005 13:24:03 +0100
Arjan van de Ven <arjan@infradead.org> wrote:

| On Tue, 2005-12-06 at 09:57 -0200, Luiz Fernando Capitulino wrote:
| >  Introduces URB write locking macros.
| 
| ugh.. WHY ?

 Because is easier to read/understand:

	if (usb_serial_write_urb_lock(port)) {
		dbg("%s - already writing", __FUNCTION__);
		return 0;
	}

 than:

	if (!atomic_add_unless(&port->write_urb_busy, 1, 1)) {
		dbg("%s - already writing", __FUNCTION__);
		return 0;
	}

 IMHO.

 Of course I'm only ilustrating the 'lock' scenario, but you will have other
atomic functions spread in the driver.

 Looks better to have some macros to make clear what you're doing.

-- 
Luiz Fernando N. Capitulino
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