From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Date: Tue, 01 Feb 2011 20:06:09 +0000 Subject: Re: Locking in the clk API, part 2: clk_prepare/clk_unprepare Message-Id: MIME-Version: 1 Content-Type: multipart/mixed; boundary="8323328-845050105-1296590771=:8580" List-Id: References: <201102011711.31258.jeremy.kerr@canonical.com> <20110201105449.GY1147@pengutronix.de> <20110201131512.GH31216@n2100.arm.linux.org.uk> <20110201141837.GA1147@pengutronix.de> <20110201143932.GK31216@n2100.arm.linux.org.uk> <20110201151846.GD1147@pengutronix.de> <20110201152458.GP31216@n2100.arm.linux.org.uk> <20110201155344.GF1147@pengutronix.de> <20110201170637.GR31216@n2100.arm.linux.org.uk> <20110201193201.GH1147@pengutronix.de> In-Reply-To: <20110201193201.GH1147@pengutronix.de> To: linux-arm-kernel@lists.infradead.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-845050105-1296590771=:8580 Content-Type: TEXT/PLAIN; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable On Tue, 1 Feb 2011, Uwe Kleine-K=F6nig wrote: > My motivation for a more complicated clk_prepare was to make clk_prepare > atomic when that's possible (i.e. when the clk is already prepared) and > call it before the enable callback in clk_enable. Then everything > behaves nicely even if clk_enable is called from atomic context provided > that the clock was prepared before (or doesn't need to). NOOOOOOOOO!!! We _do_ want drivers to _always_ call clk_prepare() in sleepable=20 context, and _then_ always call clk_enable() in whatever context they=20 wish. Period. Nicolas --8323328-845050105-1296590771=:8580--