From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Date: Tue, 01 Feb 2011 14:00:24 +0000 Subject: Re: Locking in the clk API, part 2: clk_prepare/clk_unprepare Message-Id: <20110201140024.GZ1147@pengutronix.de> List-Id: References: <201102011711.31258.jeremy.kerr@canonical.com> <20110201105449.GY1147@pengutronix.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-arm-kernel@lists.infradead.org On Tue, Feb 01, 2011 at 10:05:56PM +0900, Jassi Brar wrote: > 2011/2/1 Uwe Kleine-K=F6nig : >=20 > ..... >=20 > > Do you plan to handle the case that clk_enable is called while prepare > > isn't completed (considering the special case "not called at all")? > > Maybe BUG_ON(clk->ops->prepare && !clk->prepare_count)? > Sounds better than the second option. >=20 > > Alternatively don't force the sleep in clk_prepare (e.g. by protecting > > prepare_count by a spinlock (probably enable_lock)) and call clk_prepare > > before calling clk->ops->enable? > That might result in a driver working on some platforms(those have > atomic clk_prepare) > and not on others(those have sleeping). The first option has the same result. E.g. on some platforms clk->ops->prepare might be NULL, on others it's not. Uwe --=20 Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | http://www.pengutronix.de/ |