From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Walleij Subject: Re: [PATCH] gpio: gpio-dwapb: add optional reset Date: Wed, 11 Oct 2017 10:31:06 +0200 Message-ID: References: <20171010212617.3397-1-atull@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20171010212617.3397-1-atull@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Alan Tull , Philipp Zabel Cc: Hoan Tran , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" List-Id: linux-gpio@vger.kernel.org On Tue, Oct 10, 2017 at 11:26 PM, Alan Tull wrote: > Some platforms require reset to be released to allow register > access. > > Signed-off-by: Alan Tull Fair enough. (...) > + rst = devm_reset_control_get_optional_exclusive(dev, NULL); > + if (IS_ERR(rst)) { > + if (PTR_ERR(rst) == -EPROBE_DEFER) > + return PTR_ERR(rst); > + } else { > + reset_control_deassert(rst); > + gpio->rst = rst; > + } I do not see why any error other than -EPROBE_DEFER should be ignored? I guess the _optional API returns NULL if there is no reset line so it should be fine to just return the error on any error. > + if (gpio->rst) > + reset_control_assert(gpio->rst); Is this the right way to handle an optional reset line? Yours, Linus Walleij