From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Guo Subject: Re: [PATCH V2] spmi: pmic-arb: Enforce the ownership check optionally Date: Thu, 31 Aug 2017 16:37:29 +0800 Message-ID: <20170831083727.GA3787@dragon> References: <1503070110-15018-1-git-send-email-kgunda@codeaurora.org> <20170822085541.GB3685@dragon> <20170822203132.GC21656@codeaurora.org> <20170824121818.GE3685@dragon> <20170824183701.GN21656@codeaurora.org> <20170825074324.GF3685@dragon> <20170825231818.GP21656@codeaurora.org> <20170826034636.GG3685@dragon> <20170830210203.GS21656@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170830210203.GS21656@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Boyd Cc: Kiran Gunda , gregkh@linuxfoundation.org, Rob Herring , Mark Rutland , Abhijeet Dharmapurikar , David Collins , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-msm-owner@vger.kernel.org List-Id: devicetree@vger.kernel.org On Wed, Aug 30, 2017 at 02:02:03PM -0700, Stephen Boyd wrote: > On 08/26, Shawn Guo wrote: > > On Fri, Aug 25, 2017 at 04:18:18PM -0700, Stephen Boyd wrote: > > > > > > Right. Does the GPIO work? If so, it sounds like the read/write > > > access checks in spmi pmic arb don't work properly. > > > > The check works. With the check in there, PM8916 GPIO doesn't work. > > However, the consequence is that not only user3 but all GPIO leds under > > 'leds' node will fail to register, because any GPIO led's failing on > > create_gpio_led() makes leds-gpio driver probe fail as a while. That's > > how leds-gpio driver works. > > > > Also, per schematics, PM8916 GPIO1 is indeed routed to user3 LED on > > db410c board. Why do you think apq8016-sbc device tree shouldn't use > > the GPIO for that at all? Isn't it firmware's fault that the ownership > > of the peripheral is not properly configured? > > If the ownership was not properly configured in the firmware, > then I imagine it would mean that we can't control the GPIO for > the LED. But that doesn't seem to be true. I can see on my board > that I get impermissible write failures on the GPIO when > controlling the GPIO brightness, but it doesn't actually matter > because the led still lights up. So the checks for write/read > permission seem incorrect, or they're not being enforced. I'm not sure what is happening on your side. As I said above, with the 4.13-rc series, leds-gpio driver doesn't probe at all, due to the impermissible write to PM8916 GPIO in function create_gpio_led(), and none of the LEDs lights up on my board. Shawn