From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dY7oZ-00050K-GU for linux-mtd@lists.infradead.org; Thu, 20 Jul 2017 09:32:13 +0000 Message-ID: <1500542664.2354.27.camel@pengutronix.de> Subject: Re: [PATCH 000/102] Convert drivers to explicit reset API From: Philipp Zabel To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, "David S. Miller" , Emilio =?ISO-8859-1?Q?L=F3pez?= , Adrian Hunter , Alan Stern , Alan Tull , Alexandre Torgue , Andrew Lunn , Ben Skeggs , Benjamin Gaignard , Bin Liu , Bjorn Andersson , Bjorn Helgaas , Boris Brezillon , Brian Norris , Chanwoo Choi , Chen Feng , Chen-Yu Tsai , Corentin Labbe , Cyrille Pitchen , Dan Williams , Daniel Lezcano , David Airlie , David Woodhouse , Dmitry Torokhov , Eduardo Valentin , Felipe Balbi , Florian Fainelli , Giuseppe Cavallaro , Guenter Roeck , Hartmut Knaack , Heiko Stuebner , Herbert Xu , Jaehoon Chung , Jiri Slaby , Joachim Eastwood , John Youn , Jon Hunter , Jonathan Cameron , Jonathan Corbet , Kalle Valo , Kishon Vijay Abraham I , Kyungmin Park , Lars-Peter Clausen , Laxman Dewangan , Lee Jones , Liam Girdwood , Linus Walleij , Lucas Stach , Marc Dietrich , Marek Vasut , Mark Brown , Mark Yao , Mathias Nyman , Matthias Brugger , Maxime Coquelin , Maxime Ripard , Michael Turquette , Moritz Fischer , MyungJoo Ham , Ohad Ben-Cohen , Patrice Chotard , Peter Chen , Peter De Schrijver , Peter Meerwald-Stadler , Philippe Cornu , Prashant Gaikwad , Rakesh Iyer , Ralf Baechle , Richard Weinberger , Richard Zhu , Rongrong Zou , Ryder Lee , Salil Mehta , Shawn Lin , Srinivas Kandagatla , Stanimir Varbanov , Stephen Boyd , Tejun Heo , Thierry Reding , Thomas Gleixner , Ulf Hansson , Vincent Abriou , Vinod Koul , Vivien Didelot , Wim Van Sebroeck , Wolfram Sang , Xinliang Liu , Xinwei Kong , Yannick Fertre , Yisen Zhuang , Zhang Rui , alsa-devel@alsa-project.org, ath10k@lists.infradead.org, devel@driverdev.osuosl.org, dmaengine@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, linux-crypto@vger.kernel.org, linux-doc@vger.kernel.org, linux-fpga@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, linux-ide@vger.kernel.org, linux-iio@vger.kernel.org, linux-input@vger.kernel.org, linux-media@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-mips@linux-mips.org, linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, linux-pwm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-serial@vger.kernel.org, linux-spi@vger.kernel.org, linux-tegra@vger.kernel.org, linux-usb@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, nouveau@lists.freedesktop.org Date: Thu, 20 Jul 2017 11:24:24 +0200 In-Reply-To: <20170720081157.GA11630@kroah.com> References: <20170719152646.25903-1-p.zabel@pengutronix.de> <20170720081157.GA11630@kroah.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Greg, The patches in this series are completely independent of each other, and I would like the subsystem maintainers to apply them at their own leisure. Well, except for the last one, which I will apply only after there are no more users of the transition helpers. On Thu, 2017-07-20 at 10:11 +0200, Greg Kroah-Hartman wrote: > On Wed, Jul 19, 2017 at 05:25:04PM +0200, Philipp Zabel wrote: > > The reset control API has two modes: exclusive access, where the driver > > expects to have full and immediate control over the state of the reset > > line, and shared (clock-like) access, where drivers only request reset > > deassertion while active, but don't care about the state of the reset line > > while inactive. > > > > Commit a53e35db70d1 ("reset: Ensure drivers are explicit when requesting > > reset lines") started to transition the reset control request API calls > > to explicitly state whether the driver needs exclusive or shared reset > > control behavior. > > > > This series converts all drivers that currently implicitly request > > exclusive reset controls to the corresponding explicit API call. It is, > > for the most part, generated from the following semantic patch: > > Hey, I'm all for large api changes, but this really seems ackward, isn't > there a "better" way to do this? It is a bit awkward. I am sorry I haven't done this earlier. Quite a few new drivers started using the old API after the explicit requests were introduced last year. > Why not, as you say the "implicit" request is exclusive, just leave > everything alone and state that the "reset_control_get()" call is > exclusive I think it is better to let the drivers explicitly state what they expect from the API, and using reset_control_get_exclusive vs _shared helps driver developers to make a conscious decision. Further, the implicit API call predates shared reset support, so it is not clear that all of the old users really need exclusive control. A few drivers have been switched to the shared API already. > and make the shared one the "odd" usage as that seems to not > be the normal case. I am not sure, there have been people arguing that the "clock-like" case really is the common one. I suppose some of those drivers touched by the 100 patches in this series could also be changed to shared. But I don't dare to make this decision for each of them. > That should be a much smaller patch right? > > That way you don't break everything here, and require 100+ patches to > just change the name of a function from one to another and do nothing > else. I don't break anything here, and I'm absolutely fine with squashing patches together per subsystem where that is preferable. regards Philipp